* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download word - My eCoach
Chemical Corps wikipedia , lookup
Drug discovery wikipedia , lookup
Chemical plant wikipedia , lookup
Multi-state modeling of biomolecules wikipedia , lookup
Asymmetric induction wikipedia , lookup
Determination of equilibrium constants wikipedia , lookup
Freshwater environmental quality parameters wikipedia , lookup
Chemical industry wikipedia , lookup
Artificial photosynthesis wikipedia , lookup
Isotopic labeling wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Chemical equilibrium wikipedia , lookup
Water splitting wikipedia , lookup
Hydrogen-bond catalysis wikipedia , lookup
Electrochemistry wikipedia , lookup
Strychnine total synthesis wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Physical organic chemistry wikipedia , lookup
Rate equation wikipedia , lookup
George S. Hammond wikipedia , lookup
Lewis acid catalysis wikipedia , lookup
Electrolysis of water wikipedia , lookup
Gas chromatography–mass spectrometry wikipedia , lookup
Process chemistry wikipedia , lookup
Chemical reaction wikipedia , lookup
Click chemistry wikipedia , lookup
Bioorthogonal chemistry wikipedia , lookup
Transition state theory wikipedia , lookup
Chemical thermodynamics wikipedia , lookup
Marking Period # 3 (Enduring Understanding:___________________) California State Standard Conservation of Matter and Stoichiometry 3. The conservation of atoms in chemical reactions leads to the principle of conservation of matter and the ability to calculate the mass of products and reactants. As a basis for understanding this concept: a. Students know how to describe chemical reactions by writing balanced equations. b. Students know the quantity one mole is set by defining one mole of carbon 12 atoms to have a mass of exactly 12 grams. c. Students know one mole equals 6.02 x 1023 particles (atoms or molecules). d. Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses and how to convert the mass of a molecular substance to moles, number of particles, or volume of gas at standard temperature and pressure. e. Students know how to calculate the masses of reactants and products in a chemical reaction from the mass of one of the reactants or products and the relevant atomic masses. f. *Students know how to calculate percent yield in a chemical reaction. g. *Students know how to identify reactions that involve oxidation and reduction and how to balance oxidation-reduction reactions. *Not tested on CST NOTE: DOCUMENTS (1) TO (18) ARE STORED IN MP 3 SUPPLEMENTARY FILE Day 1 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Define mole. Distinguish between types of particles (atoms, formula units/ions, molecules) Use dimensional analysis to convert between moles and number of particles. Standard 3b, c Activity Warm Up: 1.Inspect and 2.Record mass of one mole of Pb, Cu, Zn, S, NaCl, sugar and water 3.Answer Q1and Q2 Avogadro’s No. the concept of 1 mole =6.02X1023 Use dimensional analysis for Mole Conversion Check for Understanding Objective Describe and interpret one mole of atoms, formula units (f.u.), molecules as related to the mass of elements and compounds Convert between moles and particles using conversion factors: Materials Required Samples of (a)207.2g Pb,(b)63.55g Cu; (c)65.39g Zn, (d)32.07g S; (e)58.44g NaCl; (f)342.30gsugar (C12H22O11) (g)18g water(H2O) 7 different jars Pass around classroom for observations Time 15 minutes (1) Lecture Notes and Worksheet on Mole to Particles Conversion 35 minutes 1 /2mole of H2O= ? molecules 1.2X1024 molecules of H2O=?mole 5 minutes 1mole/6.02X1023particles 6.02X1023particles/1mole Notes Discovery Demo: Q1.What is the particle/unit for each substance? elements(atoms), ionic cpds (f.u.), covalent/molecular cpds (molecules) Q2. What is the significance of the mass of each substance? (Hint: use periodic table) Students write answers of every question on board show each step Class Discussion of student work (Prentice Hall)HW: P.344 #31;36a,b;37a,b; 38a,b;39a,b Day 2 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: 3a, d Distinguish and calculate atomic mass, formula mass, molecular mass and molar mass. Convert mass of elements, ionic, molecular compounds to mole. Activity 1.Show 1 mole= 12 g of Carbon 2.Review 1 mole of the different substances as related to atomic masses Power points on conversion of molar mass of elements, ionic molecular, compounds to moles Check for understanding Objective 1.Students know the quantity of one mole is set by defining one mole of C- 12 atoms to have a mass of exactly 12 grams. 2. Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses 1.Distinguish the difference between molar mass, formula mass and molecular mass 2.Calculate molar mass/formula mass/molecular mass 3.Convert mass of elements, ionic and molecular compounds to moles Materials Required 12g Carbon And Previous day samples (13) Diagram: Formula Mass of H2O Worksheet (2) + Answers (3) on Molar Mass Calculation (4) Lecture figures on mass to mole conversion (7) Mass to Mole Power points (A) (a)1/2 mole C =? Atoms= ? g (b) 1.20 g of Carbon = ? mole (c) 5.5 g of NaCl=? Mole= ? f.u. Time 10 minutes Notes Review mole, particles and atomic masses 40 minutes Work on Practice Questions Worksheet(2) 5 minutes Students show work on board and class discussion HM Wk: P.344 #30;#32a,b; #33,a,b; #34,a,b; #35,a,b Day 3 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Convert mass of elements, ionic compounds and covalent/molecular compounds to moles to number of particles. Standard 3b, c, d Activity Objective Materials Required Review mole Convert moles of elements, ionic (8)Mass to Mole Power Points (B) to mass & mole compounds and molecular to Particles compounds to mass and particles Conversions Convert mass Summarize Mole Conversion and (5) Lecture Notes on Mole to mole to expand mass to mole to particles Conversion particles conversions (5A) In-class mole assignment Time 10 minutes Notes 5.50g NaCl=? mole 5.50X1024=? fu 40 minutes Work on practice problems in (5) & Answers (5A) Students show all work for (5) on board 6 minutes Hm Wk: 10:2 Worksheet#2, 3,67,10,11,14, 16,17 Practical Example of Conversion from mass to fu Check for understanding Discuss results based on student work (9) 10:2 Worksheet Day 4 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Convert mass to number of moles to number of particles. Standard 3b, c, d Activity Molar Quantities Lab or Hydrate Lab or Chalk MiniLab (activity sheets shown below) Check for Understanding: Class Discussion of Lab Results and Questions Objective Practice mass to mole to particles conversion Materials Required (10) Molar Quantities Lab Strips (similar size)of Pb, Cu, Zn, and about 5 g of S, NaCl, sugar, H2O, electronic scales Time 45 minutes Notes Complete Lab and Answer Lab questions 10 minutes Hm Wk: 10:2 Practice #18 to 22 Lab: Determining the Formula of a Hydrate Introduction When certain ionic solids crystallize from aqueous solutions, a definite number of molecules of water remain attached to the crystal. Ionic solids that contain a definite amount of water are called hydrates or hydrated salts and the water in the crystal structure is called water of hydration. The water is loosely bound to the ionic solid so it is possible to dehydrate or remove the water by heating. The solid that remains after all of the water is removed is said to be anhydrous. In this experiment, the formula of a hydrate, CuSO4∙xH2O, will be determined. A known mass of hydrated copper sulfate will be heated to remove all of the water. From the mass of the solid before and after heating, the number of moles of water of hydration, x will be calculated. Pre-Lab Questions: (Answer on a separate piece of paper). Washing soda is a hydrated compound whose formula can be written Na2CO3∙xH2O, where x is the number of moles of H2O per mole of Na2CO3. When a 2.123 g Na2CO3∙xH2O was heated at 130oC, all of the water of hydration was lost, leaving 0.787 g Na2CO3. (1) Calculate the mass of water lost. (2) Convert the mass of water lost to moles. (3) Convert 0.787 g Na2CO3 to moles. (4) What is the ratio of moles of H2O to moles of Na2CO3? Materials: about 2 g of copper sulfate clay triangle crucible with cover crucible tongs ring stand iron ring balance Bunsen burner Procedure: 1. Prepare the heating set-up. 2. Heat a clean crucible strongly for a minute. Allow it to cool. 3. Mass the crucible. 4. Place about 2 g of copper sulfate into the crucible and immediately mass the crucible containing the hydrate. 5. GENTLY heat the crucible. If temperature is too high, the hydrated crystals may spatter. After 2 minutes, increase the intensity of the flame slightly. Continue heating until the blue color completely disappears. 6. Allow the crucible to cool and mass it. 7. To make sure that all of the water is removed, repeat steps 5-6 until the mass of the crucible and its contents stays the same. 8. Observe the contents of the crucible. Add a few drops of water. Data and Observations: Mass of crucible (g) Mass of crucible and hydrated copper sulfate (g) Mass of crucible and anhydrous copper sulfate (after1st heating) (g) Mass of crucible and anhydrous copper sulfate (after 2nd heating) (g) Mass of hydrated copper sulfate (g) Mass of anhydrous copper sulfate (g) Mass of water lost (g) Observations: Calculations: (1) Calculate the moles of water lost. (2) Calculate the moles of anhydrous copper sulfate (CuSO4). (3) Calculate the moles of water lost per mole of anhydrous copper sulfate. Analysis and Conclusion: 1. Why must the crucible be cooled before massing? 2. What happened when you added water to the anhydrous solid? What does this indicate? 3. The correct formula for hydrated copper sulfate is CuSO4∙5H2O. Did you get the same value of x? If not what could be some possible sources of errors? 4. What is the chemical name of CuSO4∙5H2O? Mole Mini-Lab How many moles of chalk is your NAME worth? 1. Get a piece of chalk and mass it. Initial mass of chalk = __________ 2. Use the chalk to write your whole name on the pavement. 3. Mass your chalk again. Final mass of chalk = ___________ 4. Do the following calculations: (a) How many grams of chalk did you use? (b) Chalk is calcium carbonate, CaCO3. What is the molar mass of CaCO3? (c) Convert the mass of CaCO3 to moles. 5. So how many moles of chalk is your name worth? __________________________ For extra credit, calculate the number of ions of Ca2+ and CO32- that you used to write your name. DAY 5 VETERAN’S DAY HOLIDAY Day 6 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Review conversion of mass to number of moles to number of particles. Define molar volume. Convert molar volume to number of moles to mass of a gas at STP. Standard 3b, c, d Activity 1.Review on Mole Conversions Objective Review conversion from Mass to Mole to Particles 2.Molar Volume Conversion Define STP Define Molar Volume as 22.4L at STP Conversion of Volume to Mole to Mass Check for understanding Students Recreate Mole Map to enhance Mole Conversion Materials Required (11) Mole Map (6) Mole Conversion Worksheet (6A) Answers for (6) (14) Volume to Mole and Mole Map for Review (6) Mole Conversion Worksheet (9) 10:2 Practice Time 20 minutes Notes Use Mole Map to guide conversion 30 minutes Do (6) in class and HW: (9) 10:2 Practice Problems Worksheet #23 to #30 Draw Mole Map Check for X or / for mole conversion based on Mole Map 5 minutes Day 7 (Essential Question(s): ____________________________________________________________________________________) Unit Test Review (Version 1) Standard 3 a,c,d Activity Review concepts 3a,c,d Objective Prepare students to take tests: recognize what is given and what is asked for the different mole conversions Practice Skill Test Materials Required (15) and (16) Review Questions Similar to questions in STAR/SAT tests Time 56 minutes Notes Students write answers on board and show work Class discussion of all problems Taking Day 7 Unit Test Review (Version 2) A PowerPoint is attached. Review may be done using a Cooperative Learning strategy called Numbered-Heads-Together. Students working in groups of 3 figure out answer to each question together. Group member whose number is called writes the answer on white board for teacher to check. A Review Sheet is also attached. Slide 1 Slide 6 Test Review How many particles are there in 0.25 moles of a substance? Mole Concept 1.5 x 1023 particles Slide 2 Slide 7 Which of these is true? A. Different substances with the same number of moles have the same mass. B. One mole of any substance contains the same number of particles. C. Mole is a unit of energy. D. One mole of any substance contains 6.02 x 1021 particles. What is the mass of 6.02 x 1023 molecules of CO2? 44 g B Slide 3 Slide 8 What is the molecular mass of C4H10? Which is equal to 45 g of H2O? A. 1 mole B. 1.5 moles C. 2.0 moles D. 2.5 moles 58 amu D Slide 4 Slide 9 What is the molar mass of HNO3? What is the molar mass of CaCl2? 63 g 110 g Slide 5 Slide 10 How many moles are there in 60.0 g of carbon? What is the mass of 0.75 moles of CaCl2? 83 g 5.00 moles Review: Mole Concept This test will evaluate how well you can do the following: 1. Calculate the formula, molecular or molar mass of a substance. Sample Questions: A. What is the molecular mass of hydrogen peroxide (H2O2)? B. What is the molar mass of calcium chloride (CaCl2)? 2. Perform mass-mole, mole mass, mass-mole-number of particles conversion. Sample Questions: A. How many moles are in 75.0 g of water (H20)? B. What is the mass of 1.5 moles of sugar (C12H22O11)? C. How many formula units (particles) of sodium chloride (NaCl) are in 100.0 g of this substance? Day 8 Unit Test A Unit Test is attached below. Tweak it as you see fit. Unit Test: Mole Part 1. Multiple Choice. Circle the letter of the correct answer. For questions marked with an asterisk (*), show your work. 1) *Which of these substances has a molar mass of 64.0 g? A. O2 B. CH3OH C. SO2 D. CaCl2 2) What is the molar mass of CaCl2? A. 110. g B. 90.0 C. 75.0 g D. 70.0 g 3) *How many moles are contained in 9.03 x 1023 molecules of oxygen gas (O2)? A. 1.00 mole B. 1.50 moles C. 2.00 moles D. 2.50 moles 4) *How many moles are contained in 45.0 g of H2O? A. 1.00 mole B. 1.50 moles C. 2.00 moles D. 2.50 moles 5) *What is the mass of 0.750 moles of potassium chloride, KCl? A. 149 g B. 74.5 g C. 55.9 g D. 37.3 g 6) Standard temperature and pressure (STP) is A. 0oC and 2 atm B. 100oC and 1 atm C. 0oC and 1 atm D. 100oC and 2 atm 7) What is volume of a gas at STP? A. 1.0 L B. 2.4 L C. 22.4L D. 44.8 L 8) *How many moles of a gas occupy a volume of 33.6 L at STP? A. 1.00 mole B. 1.50 mole C. 2.00 mole D. 3.00 mole 9) Which is true about one mole of calcium nitrate, Ca(NO3)2? A. It has a mass of 116 g. B. It has a mass of 164 amu. C. It contains 6 oxygen atoms. D. It contains 1.204 x 1024 nitrate (NO3-) ions. 10) 9.03 x 1023 atoms of silver are placed on a balance. The balance should read A. 53.96 g B. 107.87g C. 161.81g D. 215.74g Part 2. Free Response. Answer the questions as comprehensively as you can. Make sure that calculations have correct units and correct number of significant digits. A student was tasked to determine the number of moles of water (n) in one mole of MgCl2·nH2O. She placed a small sample of MgCl2·nH2O in a dry crucible and heated it several times until all of the water has evaporated. From the mass before and after heating, she was able to determine the mass and the number of moles of water in the sample. The chart below shows the data she gathered. Mass of empty container Initial mass of sample and container Mass of sample and container after first heating Mass of sample and container after second heating Mass of sample and container after third heating 22.347 g 25.825 g 23.982 g 23.976 g 23.976 g (1) Explain why the student can correctly conclude that the hydrate was heated a sufficient number of times in the experiment. _____________________________________________________________________________________ _____________________________________________________________________________________ (2) Use the data above to (i) calculate the mass of the water that was lost upon heating (ii) calculate the number of moles of water lost when the sample was heated (iii) calculate the mass of MgCl2 that remain in the crucible. (iv) calculate the mole of MgCl2 that remain in the crucible. (v) How many moles of water are lost per mole of MgCl2? What is the formula of the hydrate? Day 9 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Recognize signs/evidences of a chemical reaction. Recognize the reactants and products in a reaction. Identify different types of chemical reactions. Standard 3a Activity Warm Up Direct Instruction and Guided Practice Evidences of Chemical Change, Reactants and Products, Types of Reaction Check for Understanding/Exit Ticket Objectives Review the difference between physical and chemical change. Students identify evidences of a chemical change, identify reactants and products and classify reactions. Materials Required Time 5 minutes Notes Physical or Chemical Change? 1. melting of ice 2. rotting of food 3. burning of gasoline 4. evaporation of water Chemical Reactions and Stoichiometry PowerPointsee Supplementary Materials folder 40 minutes The sample reactions could be shown on PowerPoint or through a demo. Reactions include: (1) Mg + HCl (2) burning of paper (3) Pb(NO3)2 + KI Demo: Mg, HCl solution, paper, matches, Pb(NO3)2 and KI solution, beaker, test tubes, droppers NaHCO3 + CH3COOH → CH3COONa + H2CO3 10 minutes NaHCO3 + CH3COOH → CH3COONa + H2O + CO2 The equations above show the reaction between baking soda and vinegar. 1) What evidences of a chemical reaction can be observed as the reaction is occurring? 2) What are the reactants of the reaction? What are the products? 3) What type of chemical reaction is it? Homework Practice Worksheet Questions 1-3 See below -Chemical Reactions and Stoichiometry Practice Worksheet The Practice Worksheet is given at the beginning of the unit. Certain questions are assigned per day for students to practice on. PowerPoint Slide Master Slide 1 Slide 5 Signs of Chemical Reactions Chemical Reactions and Stoichiometry Formation of a precipitate Precipitate – insoluble solid formed from the reaction between 2 aqueous solutions Slide 2 Slide 6 Objectives: Recognize signs of chemical reactions. Chemical Reaction and Equation Chemical reaction – a change that forms new substances Recognize the reactants and products in a Reactants – starting substances Products – new substances formed reaction. Identify different types of chemical reactions. Chemical Equation - Shorthand way of describing chemical reactions Example: 2H2 + (Reactants) Slide 3 Signs of Chemical Reactions O2 → 2H2O (Product) Slide 7 AgNO3 + NaCl → AgCl + NaNO3 What are the reactants in the above reaction? Evolution of a gas What are the products? Slide 4 Signs of Chemical Reactions Slide 8 Types of Chemical Reactions 1. Change in intensive properties like color, odor, density 2 or more reactants → Example: H2 + O2 → H2O Types of Chemical Reactions 3. Single Displacement 2 reactants 1 product 2. Decomposition 1 reactant → 2 or more products Example: H2O2 → H2O + O2 Release or absorption of energy Slide 9 Combination or Synthesis Slide 11 Types of Chemical Reactions Classify each reaction: → 2 products (active element and compound) Example: Mg + HCl → MgCl2 + H2 4. Double Displacement 2 reactants → 2 products 1. NaCl + AgNO3 → AgCl + NaNO3 2. Na + H2O → NaOH + H2 3. C2H6 + O2 → CO2 + H2O 4. Mg + O2 → MgO (2 aqueous solutions) 5. Na2CO3 → Na2O + CO2 Example: KI + Pb(NO3)2 → KNO3 + PbI2 6. KOH + HCl → KCl + H2O Slide 10 Types of Chemical Reactions 5. Combustion fuel + oxygen → water + carbon dioxide Example: CH4 + O2 → CO2 + H2O Chemical Reactions and Stoichiometry Practice Worksheet 1. Describe the different signs of chemical reactions: A. _________________________________ B. _________________________________ C. _________________________________ D. _________________________________ 2. Classify the following reactions as DECOMPOSITION, COMBINATION, SINGLE DISPLACEMENT, DOUBLE DISPLACEMENT and COMBUSTION. (a) CaCO3 → CaO + CO2 ____________________________________ (b) BaCl2 + Na2SO4 → BaSO4 + 2NaCl ____________________________________ (c) 3HNO3 + Al(OH)3 → 3H2O + Al(NO3)3 ____________________________________ (d) 2C2H2 + 5O2 → 4CO2 + 2H2O ____________________________________ (e) Na2O + H2O → 2NaOH ____________________________________ (f) Mg + 2HCl → MgCl2 + H2 ____________________________________ 3. Name the type of reaction described below. ___________________ (a) a complex compound breaks down into simpler compounds or into its constituent elements ___________________ (b) two or more elements or simpler compounds react to form a single more complex compound ____________________ (c) a more active element displaces a less active one from its compound ____________________ (d) reaction between two solutions of ionic compounds ____________________ (e) reaction that requires oxygen as a reactant and produces carbon dioxide and water 4. Write a chemical equation for each chemical reaction described below. A.) Magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas (H2). What are the reactants? ________________________________________________________ What are the products? ________________________________________________________ Chemical Equation: ___________________________________________________________ B.) Iron reacts with oxygen (O2) in air and forms iron(III) oxide. What are the reactants? ________________________________________________________ What are the products? _________________________________________________________ Chemical Equation: ____________________________________________________________ C.) Two clear, colorless solutions of potassium iodide and lead(II) nitrate react with each other and produce potassium nitrate and lead(II) iodide, a yellow precipitate. What are the reactants? _______________________________________________________ What are the products? _______________________________________________________ Chemical Equation: __________________________________________________________ 5. What type of reaction will most likely occur to the given reactant(s)? Complete the equation by predicting the products of the reaction. A) Fe(s) + HCl(aq) → B) AgNO3(aq) + NaCl(aq) → C) Mg(s) + CuSO4(aq) → D) Ag2O → E) KOH(aq) + BaCl(aq) → F) C4H10(g) + O2 (g) → G) Na(s) + O2(g) → 6. Complete the paragraph. According to the Law of __________________________________, mass remains the same before and after a chemical reaction. This is because atoms are not ___________________________ nor _______________________ during a chemical reaction. The number and kind of atoms do not change. This is shown in a balanced chemical equation where the same number of atoms is written on each side of the equation. To balance an equation, ________________________ are written before the formula of the reactants and products. 7. Balance these chemical equations: A.) Ca B.) H2O2 C.) N2 D.) E.) + O2 → → H2 H2 → Cu2O + C CO2 + H2O → + CaO + O2 NH3 → Cu + CO2 C6H12O6 + O2 Solve the following stoichiometric problems. Show your work. 8. Mole-Mole Problems In the chemical reaction, Mg + 2HCl → MgCl2 + A. how many moles of magnesium are needed to produce 3.00 moles of hydrogen gas? H2 B. how many moles of magnesium chloride can be produced from 4.00 moles of hydrogen chloride? In the reaction, 4Fe + 3O2 → 2Fe2O3 C. how many moles of oxygen are needed to react with 2.00 moles of iron? D. how many moles of iron and oxygen are needed to produce 6.00 moles of iron (III) oxide? 9. Mole-Mass Problems In the chemical reaction, Mg + 2HCl → MgCl2 + A. how many moles of magnesium are needed to produce 4.00g of hydrogen gas? H2 B. how many grams of magnesium chloride can be produced from 2.00 moles of magnesium? In the reaction, 4Fe + 3O2 → 2Fe2O3 C. how many grams of iron are needed to form 4.00 moles of iron (III) oxide? D. how many moles of oxygen are needed to completely react with 112 g of Fe? 10. Mass-Mass Problems In the chemical reaction, C6H12O6(g) + 6O2(g) → 6CO2(g) + 6H2O(g) A. how many grams of carbon dioxide can be produced from the burning of 180.0 g of glucose (C6H12O6)? B. what is the mass of oxygen needed to produce 54.0 g of water? In the chemical reaction, 2Mg + CO2 → 2MgO + C. how many grams of carbon dioxide are needed to produce 36.0 g of C? C D. what is the mass of magnesium oxide that can be produced from 36.0 g of magnesium? 11. Molar Volume In the chemical reaction, Mg(s) + 2HCl(aq) → MgCl2(aq) + A) how many liters of hydrogen gas at STP is produced from 2.50 moles of magnesium? H2(g) B) how many liters of hydrogen gas at STP is produced from 18.0 g of magnesium? In the chemical reaction, C6H12O6(g) + 6O2(g) → 6CO2(g) + 6H2O(g) C) How many liters of oxygen are needed to produce 12.0 moles of carbon dioxide at STP? D) How many liters of carbon dioxide are produced from 16.0 L of oxygen at STP? 12. Limiting and Excess Reactants A) 2 slices of bread + 3 slices of ham For the burger “reaction”, complete the table below: Number of Number of Ham Number of Bread Slices Slices Sandwiches 10 20 20 24 6 6 20 12 10 12 → Name of Limiting “Reactant” 2 sandwiches Name of Excess “Reactant” Excess amount ham 20 slices bread 10 slices B) Hydrogen gas reacts with oxygen gas to form water vapor according to the reaction below: 2H2(g) + O2(g) → 2H2O(g) For this reaction, complete the table below: Amount of Hydrogen Amount of Oxygen 10 moles 8 moles 20 moles 6 moles 4g 40 g 10 g 64 g 2L 2L 12 L 4L Amount of Water Vapor Name of Limiting Reactant Name of Excess Reactant Excess Amount 13. Theoretical and Percent Yield A. In the chemical reaction, 2Mg + CO2 → 2MgO + C if only 58 g of MgO is actually produced from 36.0 g of Mg, what is the percent yield of the reaction? B. What is the percent yield of the reaction shown below if 11.0 g of hydrogen reacts completely with nitrogen to form 40.8 g of ammonia? N2 + 3H2 → 2NH3 Day 10 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Write chemical equations from word equations. Standard 3a Activity Warm Up Objectives Review identifying reactants and products and classifying reactions. Materials Required Time 5 minutes Notes Al + O2 → Al2O3 1. What is/are the reactant(s) of the reaction shown above? 2. What type of reaction is it? Explain. Direction Instruction: Predicting Products Students view the reaction between sodium and chlorine. They identify the reactants and product of the reaction. They will then be guided in writing the chemical equation for the reaction. Youtube video of reaction between sodium and chlorine – see link below 10 minutes Guided Practice Students look at other chemical reactions. Working in groups, they practice identifying reactants and products and writing chemical equations. Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder 30 minutes Check for Understanding/Exit Ticket Provide evidence of mastery of the day’s learning objectives. Homework Practice Worksheet Question 4 10 minutes An ancient sword made of pure iron is found. The sword has reacted with oxygen gas over the course of hundreds of years to form iron(III) oxide. Write the equation for this reaction. See below -Chemical Reactions and Stoichiometry Practice Worksheet Youtube video of reaction between sodium and chlorine http://www.youtube.com/watch?v=Mx5JJWI2aaw PowerPoint Slide Master Slide 12 Slide 15 Learning Objective: Write the chemical equation for this reaction: Blue copper(II) sulfate solution reacts with iron to form iron(II) sulfate and copper. Write chemical equations from word equations. Reactants: Copper(II)sulfate and iron Products: Iron (II)sulfate and copper Chemical Equation: CuSO4 + Fe → Slide 13 Chemical Equations Steps in writing chemical equations: 1. Identify the reactants and the products. 2. Write the formulae (or symbols) of the reactants before the arrow. 3.Write the formulae (or symbols) of the products after the arrow. Slide 14 Chemical Equations Example: When magnesium (Mg) is heated, it reacts with oxygen (O2) in air and burns to produce magnesium oxide (MgO). Reactants: magnesium (Mg) and oxygen (O2) Products: magnesium oxide (MgO) Chemical Equation: Mg + O2 MgO Slide 16 FeSO4 + Cu Write the chemical equation for each reaction: 1. Silver oxide decomposes into silver and oxygen gas when heated. 2. Ethanol (C2H5OH) burns completely by reacting with oxygen in air. Carbon dioxide and water vapor are produced. 3. Aluminum bromide is produced when aluminum reacts with bromine. Day 11 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Classify 5 Different Types of Chemical Reactions Standard 3a Activity Demo of single displacement double displacement reactions Objective Classify 5 different types of chemical reactions starting with single displacement Materials Required (17) 2MCuCl2, Al 1MBaCl2, 1M Na2SO4 Time 5 minutes Demo double displacement reactions Differentiate between single and double displacements 1M BaCl2, 1M Na2SO4 5 minutes Introduce synthesis,decomposition & combustion Check for understanding Notes Observe reaction, understand mechanism of different types of reactions : 1. Observe reaction, 2. write balanced equation, 3. Predict products and write balanced equations Practice classify , predict products, and write balanced equations (18) (18A) (18B) (18C) Students write balanced equations on board and Class discussion HW: Prelab for “Chemical Activities of metals PowerPoint Slide Master Slide 17 Slide 20 Objective: Predicting Products Predict the products of common chemical C6H14 + O2 → _________ reactions. What type of reaction will most likely occur between the 2 reactants? What are the products? C6H14 Slide 18 + O2 → CO2 + H2O Slide 21 Predicting Products Al + HCl → Predict the products of the reaction: _________ What type of reaction will most likely occur between the 2 reactants? What are the products? Al + HCl → AlCl3 + H2 Slide 19 Predicting Products CuCl2(aq) + Pb(NO3)2 (aq) → _________ What type of reaction will most likely occur between the 2 reactants? What are the products? CuCl2(aq) + Pb(NO3)2 (aq) → Cu(NO3)2 (aq) + PbCl2 (s) 1. NaOH(aq) + FeCl3(aq) → 2. Zn(s) + HNO3(aq) → 3. C4H10(g) + O2(g) → 4. N2(g) + H2(g) → 5. KBr(aq) + Cl2(g) → Day 12(Essential Question(s): ____________________________________________________________________________________) (Version 1) Learning Objectives: Compare chemical activities of Cu, Zn, Mg and Ag Predict products of reaction, write balanced chemical equations Standard 3a Activity Chemical Activity of Metals Lab Objective Observe single displacement reactions of Cu,Zn,Mg,Ag Write balanced equations of all reacted reactions Materials Required (18)(18A)(18B)(18C) Time 56 minutes Notes Develop critical thinking skill and based on results to predict reactions and write balanced chem. equations Day 12 (Essential Question(s): ____________________________________________________________________________________) (Version 2) Learning Objective: Predict the products of common chemical reactions. Standard 3a Activity Warm Up Objective Students predict whether mass will increase, decrease or decrease in the reaction between Alkaseltzer and water in a sealed ziplock bag. Materials Required Time 10 minutes Notes To give students hints on how to write the experimental procedure, provide them a list of materials they may use. Per group: 1 ziplock bag 1 Alkaseltzer tablet cup with water triple beam balance 10 minutes Procedure: (1) Place ¼ cup water in ziplock bag. (2) Place ziplock bag with water and an Alkaseltzer tablet on balance pan. Record mass. (3) Add Alkaseltzer tablet to the water and immediately seal the bag. Weigh again. Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder 10 minutes They will also write a simple procedure for testing their prediction. Alkaseltzer Mini-Lab Direct Instruction: Law of Conservation of Mass and Balancing Equations Guided Practice on Balancing Equations Students test prediction. their 20 minutes Check for Understanding/Exit Ticket 1) 24 grams of carbon completely reacts with 64 grams of oxygen gas. What mass of carbon dioxide is produced? C + O2 CO2 24g 64g ? 2) Balance the following equation: Al + Fe2O3 → Al2O3 + Fe Homework Practice Worksheet, Questions 6-7 See attached Chemical Reactions and Stoichiometry Practice Worksheet PowerPoint Slide Master Slide 22 Slide 26 Objectives: Balanced Chemical Equations Balanced Equation – the number of atoms of each element is equal on both sides of the equation Recognize that chemical reactions are governed by the Law of Conservation of Mass. How to balance equations: 1. Count the number of atoms of each element. 2. Use coefficients to make the number of atoms of each element equal. 3. DO NOT change any of the subscripts. Balance chemical equations. Slide 23 Slide 27 Law of Conservation of Mass Balancing Chemical Equations Example 1: Mg + 2 HCl Reactants: Mg – 1 H–1 X2=2 Cl – 1 X 2 = 2 Burning Magnesium Metal in an Open Container → MgCl2 + Products: Mg – 1 H–2 Cl - 2 Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 77 Slide 24 Law of Conservation of Mass Slide 28 Balancing Chemical Equations Example 2: + 2 H2O → 2 NaOH+ H2 2 Na Reactants: Products: Na – 1 X 2 = 2 Na – 1 X 2 = 2 H–2 X2=4 H–1X2+2 =4 O–1 X2=2 O-1 X2=2 Burning Magnesium Metal in a Closed Container Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 77 Slide 25 Law of Conservation of Mass The total mass of reactants is equal to the total mass of the products. Matter is neither created nor destroyed in a chemical reaction. 2Mg 48 g Slide 30 + O2 → 32 g 2MgO ? Closure: Write-Pair-Share 1.In your own words, describe how a chemical equation is balanced. 2. Share your answer with your group mates. 3. Make sure that everyone in the group has the correct answer to the question. 4. If your group is chosen and is able to give the correct answer, you earn 3 extra credit points. Slide 29 Balancing Chemical Equations Balance the following equations: 1. Na + Cl2 → NaCl 2. Fe + O2 → Fe2O3 3. Zn + HCl → ZnCl2 + H2 4. KNO3 → KNO2 + O2 H2 Day 13 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Balance chemical equations. Standard 3a Activity Warm Up Objective Review balancing of equations. Materials Required Time 5 minutes Independent Practice This will allow – Balancing Equations students to practice further and master the skill of balancing equations See Pogil-Balancing Equations (pdf file) 35 minutes Youtube video of the reaction – see link below. 10 minutes Check for Understanding/Exit Ticket Students write a balanced chemical equation for the reaction between iron and sulfur. Notes KClO3 → KCl + O2 Is the above equation balanced? Why or why not? Balance the equation if it’s not. It is suggested that this activity be done in small groups so students will have a chance to discuss and clarify concepts and to check each other’s work. Demo – see Activity Sheet below You may show a video of the reaction or demonstrate it yourself. Reaction of Iron and Sulfur Video: http://www.youtube.com/watch?v=A5H6DVe5FAI&feature=related&safety_mode=true&persist_safety _mode=1 Day 14 & 15 Thanksgiving Holiday Day 16 (Essential Question(s): ____________________________________________________________________________________) Learning Objectives: Identify the type of chemical reaction. Predict the products of common chemical reactions. Write balanced chemical equations. Standard 3a Activity Warm Up Objective Go over the objective, procedure and safety precautions of the lab. Materials Required Time 10 minutes Rotational Lab Stations – Types of Reactions In this lab activity, students will put together and apply the skills they have been practicing the past several days – classifying reactions, predicting products and writing balanced equations. Check students’ completed activity sheet. Practice Worksheet Question 5 See the materials listed on the Activity Sheet – see below 40 minutes Check for Understanding/Exit Ticket Homework 5 minutes See above - Chemical Reactions and Stoichiometry Practice Worksheet Notes Lab: Types of Reactions Purpose: Predict products of a reaction and write chemical equations. Lab Station 1: Reaction between calcium carbonate and dilute hydrochloric acid Prediction: What type of reaction will most likely occur? What products will most likely form? Explain. _____________________________________________________________________________ _____________________________________________________________________________ Materials: 50-mL beaker, tiny scoop or spatula, dropper, dilute hydrochloric acid solution, solid calcium carbonate, waste container Procedure: Place a small sample of calcium carbonate in the beaker. Add drops of hydrochloric acid. Observe. Write an equation for the reaction. Dispose of the used chemicals in the waste container and clean the beaker. Observation: ______________________________________________________________ Chemical Equation: _________________________________________________________ Lab Station 2: Reaction between solutions of sodium hydroxide and iron(III) nitrate Prediction: What type of reaction will most likely occur? What products will most likely form? Explain. _____________________________________________________________________________ _____________________________________________________________________________ Materials: test tube, 2 droppers, sodium hydroxide solution, iron(III) nitrate solution, waste container Procedure: Mix ten drops of sodium hydroxide solution with ten drops of iron(III) nitrate solution. Observe. Write an equation for the reaction. Dispose of the used chemicals in the waste container and clean the beaker. Observation: ______________________________________________________________ Chemical Equation: _________________________________________________________ Lab Station 3: Reaction between iron and copper(II) sulfate solution Prediction: What type of reaction will most likely occur? What products will most likely form? Explain. _____________________________________________________________________________ _____________________________________________________________________________ Materials: small test tube, small iron nail, copper(II) sulfate solution, sandpaper, waste container Procedure: Half-fill a small test tube with copper(II) sulfate. Place the iron nail in the solution. Observe. Write an equation for the reaction. Dispose of the used solution in the waste container. Use sand paper to remove the copper that adheres to the surface of iron nail. Observation: ______________________________________________________________ Chemical Equation: _________________________________________________________ Lab Station 4: Burning ethanol (C2H5OH) Prediction: What type of reaction is this? What products will most likely form? _____________________________________________________________________________ _____________________________________________________________________________ Materials: dollar bill, large beaker with 50% ethanol solution, large beaker with water, tongs, matches, paper towel Procedure: Holding the dollar bill with a pair of tongs, dip it in the beaker of ethanol solution. With a match, light the dollar bill. Burn the ethanol but not the dollar bill. To prevent dollar bill from burning, dip it in the beaker of water. (If you burn the dollar bill, you have to pay for it!). Dry the dollar bill for the next group to use. Write down observations and chemical equation. Observation: ______________________________________________________________ Chemical Equation: _________________________________________________________ Lab Station 5: Removing water from copper(II) sulfate pentahydrate, CuSO4∙5H2O Prediction: What type of reaction is this? What products will most likely form? _____________________________________________________________________________ _____________________________________________________________________________ Materials: test tube, small scoop or spatula, Bunsen burner, dropper, copper(II) sulfate pentahydrate, beaker of water Procedure: Place a tiny sample of solid copper(II) sulfate pentahydrate in a test tube. Take note of the color. Gently heat the test tube until the solid changes color. Cool down the test tube and add a few drops of water. Write down observations and chemical equation. Observation: ______________________________________________________________ Chemical Equation: _________________________________________________________ Day 17 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Convert moles of reactants to moles of products and vice versa. Standard 3a, e Activity Warm Up Objective Students interpret a recipe and relate it to interpreting balanced chemical equations. Materials Required Time 10 minutes Notes 1) 1 bun + 2 patties + 2 cheese → 1 cheeseburger How many patties are needed to make 5 cheeseburgers? 2) 2H2 + O2 →2H2O Direct Instruction: Mole-Mole Conversion Show students how the conversion is done through dimensional analysis. Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder Guided Practice Check for Understanding/Exit Ticket 15 minutes 20 minutes Provide evidence of mastery of the day’s learning objective. 10 minutes How many moles of hydrogen are needed to make 4 moles of water? Emphasize that mole ratio (conversion factor) is based on balanced equation. The coefficients indicate number of moles. Write steps on board so students can refer to them as they do the practice: 1. Identify known and unknown. 2. Write possible conversion factors. 3. Set up equation using appropriate factors (do the known units cancel)? 4. Check answer. (sig figs and unit?) True or False: In the reaction shown below, it takes 1.25 moles of N2 to produce 2.50 moles of NH3. N2 + 3H2 → 2NH3 Support your answer with a calculation. Homework Practice Worksheet, Question 8, 1-d See above - Chemical Reactions and Stoichiometry Practice Worksheet PowerPoint Slide Master Slide 31 Slide 35 Learning Objective: Mole-Mole Conversion 2H2 + Convert moles of reactants to moles of products O2 → 2H2O Ex.1 : How many moles of water can be produced from 3.50 moles of hydrogen? and vice versa. Given: 3.50 mol H2 Unknown: mol H2O Possible conversion factors: 2mol H2 2 mol H2O Derived from balanced equation 2 mol H2O 2mol H2 Equation: moles of H2O Slide 32 Slide 36 Stoichiometry x + O2 → Given: 5.0 mol O2 balanced equations. Equation: moles of H2 Slide 37 3. Set up equation using appropriate conversion factor(s). x mole of unknown mole of known Do the known units cancel? 4. Check answer. Sig figs? Units? Mole-Mole Conversion 2H2 + 2 moles O2 → 1 mole x 2 mol H2 1 mol of O2 = 10. moles H2 + 2 HCl → MgCl2 + H2 1. How many moles of magnesium are needed to produce 0.500 moles of magnesium chloride? 2.Write possible conversion factors. Slide 34 = 5.0 mol O2 Practice Problems: Mg mole unknown = mole of known 2mol H2 1 mol O2 1 mol O2 2mol H2 - Stoichiometric calculations are based on 1.Identify given and unknown. 2H2O Unknown: mol H2 Possible conversion factors: moles, mass or volume (gases). Solving Stoichiometric Problems = 3.50 mol H2O Ex. 2: How many moles of hydrogen are needed to react with 5.0 moles of oxygen? - Amount is usually expressed in number of Slide 33 2 mol H2O 2 mol of H2 Mole-Mole Conversion 2H2 -Stoichiometry is the calculation of the amount of reactants and products in a chemical reaction. = 3.50 mol H2 2H2O 2 moles Coefficient – indicates number of moles 1.How many moles of oxygen are needed to produce 2 moles of water? Answer: 1 mole of oxygen 2. How many moles of water can be produced from 4 moles of hydrogen? Answer: 4 moles of water 3. How many moles of hydrogen is needed to react with 2 moles of oxygen? Answer: 4 moles of hydrogen 2. How many moles of hydrogen gas can be produced from 6 moles of magnesium? Day 18 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Do mass-mole conversions of reactants and products. Standard 3a, e Activity Warm Up Objective This is a review of molar mass to prepare students to do mass-mole conversions. Materials Required Time 10 minutes Notes What is the mass of a mole of: 1) N2H4 2) Ca(NO3)2 Direction Instruction – Mole-Mass Conversion Guided Practice Check for Understanding/Exit Ticket Show students how the Chemical Reactions and conversion is done Stoichiometry through dimensional PowerPoint- see analysis. Supplementary Materials folder 15 minutes Emphasize: Molar mass is used to do mole-mass conversion. 20 minutes Write steps on board so students can refer to them as they do the practice: 1. Identify known and unknown. 2. Write possible conversion factors. 3. Set up equation using appropriate factors (do the known units cancel)? 4. Check answer. (sig figs and unit?) Provide evidence of mastery of the day’s learning objective. 10 minutes 2KClO3 → 2KCl + 3O2 How many grams of KCl can be produced from 0.50 moles of KCl? (a) Name the given and the unknown in the problem. (b) What possible conversion factors can you use to solve the problem? (b) Show how the equation should be set up. Homework Practice Worksheet, Question 9, 1-d See above - Chemical Reactions and Stoichiometry Practice Worksheet PowerPoint Slide Master Slide 38 Mole-Mass or Mass-Mole Conversion Given Molar mass mol B = mass A x mass B = mol A x Slide 39 Mole ratio from balanced equation 1 mol A x mol B mass A mol A mol B mol A x mass B 1 mol B Mole-Mass or Mass-Mole Conversion 2H2 + O2 → 2H2O Ex.1 : What is the mass of oxygen that is needed to produce 4.0 moles of water? Given: 4.0 mol H2O Unknown: g of O2 Possible conversion factors: 1 mol O2 2 mol H2O Equation: mass of O2 = 4.0 mol H2O x Slide 40 32g O2 1 mol O2 1 mol O2 x 32g O2 = 64 g O2 2 mol H2O 1 mol O2 Practice Problems: Mg + 2 HCl → MgCl2 + H2 1.How many moles of magnesium are needed to form 47 grams of magnesium chloride? 2. How many grams of magnesium are needed to produce 4.5 moles of hydrogen? Day 19 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Do mass-mass conversions of reactants and products. Standard 3a, e Activity Warm Up Objective Review mole-mass conversion. Materials Required Time 10 minutes Direct Instruction – Mass-Mass Conversion Show students how the conversion is done through dimensional analysis. Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder 15 minutes Guided Practice Check for Understanding/Exit Ticket Provide evidence of mastery of the day’s learning objectives. Notes N2 + 3H2 → 2NH3 How many grams of ammonia can be produced from 1.50 moles of hydrogen gas? 20 minutes Write steps on board so students can refer to them as they do the practice: 1. Identify known and unknown. 2. Write possible conversion factors. 3. Set up equation using appropriate factors (do the known units cancel)? 4. Check answer. (sig figs and unit?) 10 minutes Mg + CuSO4 → MgSO4 + Cu How many grams of Cu can be produced when 5.00 g of Mg reacts completely with CuSO4? (a) What are the steps in solving the above problem? Give the correct conversion factor for each step. (b) Set up an equation that shows the conversion factors you listed in (a). Homework Practice Worksheet, Question 10, 1-d See above - Chemical Reactions and Stoichiometry Practice Worksheet PowerPoint Slide Master Slide 41 Mass- Mass Conversion 2H2 2(2g) = 4g + O2 1(32g) = 32 g → 2H2O 2 (18g) = 36g 1. How many grams of hydrogen are needed to produce 36 g of water? Answer: 4g hydrogen 2. How many grams of water can be produced from 32 g of oxygen? Answer: 36 g water 3. What is the mass of oxygen that is needed to react with 8 g of hydrogen? Answer: 2(32g) = 64 g Slide 42 Mass -Mass Conversion mass B = mass of A x 1 mole A mass A 2H2 + O2 x mole B mole A → x mass B 1 mole B 2H2O Ex.1 : What is the mass of oxygen that is needed to produce 18 g of water? Given: 18 g of H2O Unknown: g of O2 Possible conversion factors: 1 mol H2O 18 g H2O Equation: mass of O2 = 18 g H2O x 1 mol H2O 18 g H2O Slide 43 1 mol O2 32g O2 2mol H2O 1 mol O2 x 1 mol O2 x 32 g O2 = 16 g O2 2 mol H2O 1 mol O2 Practice Problems: Mg + 2 HCl → MgCl2 + H2 1. How many grams of magnesium are needed to produce 6g of hydrogen? 2. How many grams of magnesium chloride can be produced from 54 g magnesium? Day 20 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Convert mass to mole to molar volume of gaseous reactants and products at STP. Standard 3a, d, e Activity Warm Up Objective Review mass-mole conversion. Materials Required Time 5 minutes Notes Zn + HCl → ZnCl2 + H2 How many moles of hydrogen gas can be prepared from the reaction of 2g of Zn with excess HCl? Demo – Hydrogen Balloon Explosion Hydrogen gas will be generated from the reaction between Zn (or Mg) and HCl. Given the mass of Zn used in the reaction, guide the students in figuring out the volume of the hydrogen gas produced, assuming standard conditions for pressure and temperature. From the balanced equation for the reaction between H2 and O2, let the students figure out the volume of O2 needed to completely burn the H2 gas. Guided Practice Check for Understanding/Exit Ticket See Activity Sheet below 25 minutes Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder 20 minutes 2C4H10 + 13O2 → 8CO2 + 10H2O 5 minutes If 0.33 moles of butane (C4H10) are burned, how many liters of carbon dioxide would be produced at STP? Homework Practice Worksheet, Question 11 a-d See above - Chemical Reactions and Stoichiometry Practice Worksheet Be aware of the safety precautions that must be observed in demonstrating the ignition of H2 gas. See Activity Sheet below. PowerPoint Slide Master Slide 44 Slide 47 Learning Objectives: Practice Problems: Mg Perform mass-mole-volume conversion at STP. 2 HCl → MgCl2 + H2 1. How many grams of magnesium are needed to produce 11.2 L of hydrogen gas at STP? Perform volume-volume conversion of gaseous 2. How many liters of hydrogen gas at STP may be produced from the reaction of 15.0 g of magnesium with excess hydrochloric acid? reactants and products at STP. Slide 45 + Slide 48 Molar Volume Volume -Volume Conversion (at STP) L of B = L of A x Avogadro’s Principle: Equal volumes of gases at the same temperature and pressure contain the same number of particles. 2H2 + O2 → mol B mol A 2H2O Ex.1 : How many liters of oxygen gas are needed to completely react with 13.5 L of hydrogen gas at STP? At STP (Standard Temperature and Pressure), Given: 13.5 L H2 1 mole of any gas occupies a volume of 22.4 L. Unknown: L of O2 Possible conversion factors: 1mol O2 2 mol H2 Equation: L of O2 = 13.5 L H2 x 1mol O2 = 6.75 L O2 2 mol H2 Slide 46 Mass-Mole-Volume Conversion (at STP) L of B = mass of A x 2 KClO3 1 mol A mass A → x mol B mol A x 22.4 L B 1 mol B 2KCl + 3O2 Ex.1 : How many liters of oxygen gas are produced when 30.0 g of potassium chlorate decomposes at STP? Given: 30.0 g KClO3 Unknown: L of O2 Possible conversion factors: 1 mol KClO3 3mol O2 22.4 L O2 122.5 g KClO3 2mol KClO3 1 mol O2 Equation: L of O2 = 30.0 g KClO3 x 1 mol KClO3 x 3 mol O2 x 22.4 L O2 = 8.23 L O2 122.5 g KClO3 2 mol KClO3 mol O2 Slide 49 Practice Problems: N2(g) + 3H2(g) → 2 NH3(g) 1. How many liters of hydrogen gas are needed to completely react with 40.0 L of nitrogen gas at STP? 2. How many liters of ammonia gas may be produced when 50.0 L of hydrogen gas react with excess nitrogen gas at STP? Day 22 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Distinguish between limiting and excess reactants. Standard 3f(not tested on CST) Activity Warm Up Objective 1 bun + 2 patties + 2 cheese slices → 1 cheeseburger Materials Required Time 10 minutes Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder 15 minutes If there are 8 buns, 12 patties and 12 cheese slices available, how many cheeseburgers can we make? Direction Instruction – Solving limiting and excess reactant problems Guided Practice Check for Understanding/Exit Ticket Ingredients needed for making pancakes: 1 cup flour, ½ cup milk, 1 egg Ingredients available on hand: 2 cup flour, 2 cups milk, 2 eggs 10 minutes 1.Which of the available ingredient(s) is/are in excess? 2. Which of the available ingredient(s) limit(s) the amount of pancakes that can be made? 2H2 + O2 → 2H2O 3. If 1.50 moles H2 and 0.50 moles O2 react, will both reactants be completely consumed? If not, name the excess reactant. Homework Practice Worksheet – Question 12 a-b 20 minutes See above - Chemical Reactions and Stoichiometry Practice Worksheet Notes Using food recipes as examples is an engaging way to introduce the difficult concepts of limiting and excess reactants. You may have students suggest their own recipes and have them come up with similar questions as on the warm up. PowerPoint Slide Master Slide 50 Slide 53 Learning Objective: Limiting and Excess Reactants 2H2 Distinguish between limiting and excess + O2 → 2H2O Ex.1: 6.0 g of H2 and 60.g of O2 are made to react. reactants. (a) Is there a reactant present in excess? If there is, how many grams of this reactant is left unreacted? (b) How many grams of water are produced from the reaction? mass of O2 = 6.0 g H2 x 1 mol H2 x 1 mol O2 x 32g O2 = 48 g O2 2 g H2 2 mol H2 1 mol O2 Only 48 g of O2 is needed to completely react, so it is an excess reactant. 12 g of O2 is left over. Slide 51 Limiting and Excess Reactants Slide 54 Limiting and Excess Reactants 2H2 1 bun + 2 patties + 2 cheese slices → double cheeseburger + O2 → 2H2O Ex.1: 6.0 g of H2 and 60.g of O2 are made to react. If there are 5 buns, 8 patties and 6 cheese slices available, how many double cheeseburgers can be made? (a) Is there a reactant present in excess? If there is, how many grams is left unreacted? (b) How many grams of water are produced from the reaction? H2 is the limiting reactant; it determines the amount of water produced. Which ingredient is completely used up? mass of H2O = 6.0 g H2 x 1 mol H2 x 2 mol H2O x 18 g H2O = 54g H2O 2 g H2 2 mol H2 1 mol H2O Which ingredient is left over? Slide 52 Limiting and Excess Reactants Slide 55 Practice Problems: 2Al Limiting Reactant – completely used up; limits the amount of product Excess Reactant – not completely used up, “left over” + 3Br2 → 2AlBr3 20 g aluminum and 100.0 g bromine were made to react. 1. What is the limiting reactant in the reaction? 2. How much of the excess reactant is left over after the reaction? 3. How many grams of aluminum bromide is produced from the reaction? Day 23 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Calculate the theoretical yield and percent yield of a reaction. Standard 3f(not tested on CST) Activity Warm Up Description/Details Review mass-mass conversion. Materials Required Time 10 minutes Students offer possible explanations for why actual yield is usually less than theoretical yield. Direct Instruction and Guided Practice – Solving Theoretical and Percent Yield Problems Chemists often get less than the maximum amount of product that they expect from a reaction. Why do you think this is so? Chemical Reactions and Stoichiometry PowerPoint- see Supplementary Materials folder Pre-Lab Discussion – Preparation of Salt Go over objective, procedure and safety precautions of the lab. Check for Understanding/Exit Ticket Provide evidence of mastery of the day’s learning objective. Notes 2Na + Cl2 → 2NaCl What is the maximum amount (in grams) of NaCl that can be produced if 56.0 g sodium reacts with excess chlorine? 30 minutes 10 minutes The lab may be modified by giving only general directions and having the students figure out the procedure on their own. For example, you may instruct them to prepare sodium chloride from 1 g of baking soda and excess HCl. Have them figure out ways to minimize errors and maximize the yield of the reaction. Their procedure should also include safety precautions. If this modification is made, 1 more period is needed for students to work with their group mates in formulating the procedure. NaHCO3 + HCl → NaCl + H2O + CO2 How many grams of NaCl may be produced if 8.40g NaHCO3 reacts completely with excess HCl solution? What is the percent yield of the reaction, if only 4.0 g NaCl is actually produced? Homework Answer Pre-lab Questions – Preparation of Salt PowerPoint Slide Master Slide 56 Slide 59 Learning Objective: Sample Problem 2 Mg + 2 HCl → MgCl2 + H2 Determine the theoretical and percent yield of a reaction. 1.How many grams of hydrogen are formed from 24 g magnesium? Answer: 2 g 2. If only 1g of hydrogen is actually produced from 24 g magnesium, what is the % yield of the reaction? Answer: Slide 57 Theoretical and Percent Yield Theoretical Yield – amount of product formed when all of the reactants are completely used up Actual Yield – amount of product actually formed in a reaction Usually: Actual Yield < Theoretical Yield Percent Yield – indicates how well a reaction comes to completion Percent Yield = Slide 58 Actual Theoretical x 100 Sample Problem 1 2H2 2(2g) = 4g + O2 1(32g) = 32 g → 2H2O 2 (18g) = 36g 1. How many grams of water can be produced from 32 g of oxygen? Answer: 36 g water (theoretical yield) 2. If only 27 g of water is actually produced from 32 g of oxygen, what is the % yield of the reaction? Answer: % yield = 27 x 100 = 75% 36 Slide 60 % yield = 1g x 100 = 50% 2g Check for Understanding 2KClO3 → 2KCl + 3O2 What is the % yield of the above reaction if only 45 g of oxygen is produced from 122 g of potassium chlorate? Day 24 (Essential Question(s): ____________________________________________________________________________________) Learning Objective: Calculate the theoretical yield and percent yield of a reaction. Standard 3f(optional) Activity Warm Up Lab – Preparation of Salt Check for Understanding/Exit Ticket Homework Description/Details Students review the procedure and safety precautions with their group mates. In this lab activity, students will apply the skills they have been practicing the previous days – doing mass – mass conversion and calculating theoretical and percent yield. Check data and calculations. Answer analysis questions and write conclusion. Materials Required See Activity Sheet below for list of materials Time 5 minutes 45 minutes 5 minutes Notes Lab: Preparation of Salt Overview and Purpose: The percent yield of a reaction will be determined in this experiment by comparing the actual mass of product formed from the reaction with the theoretical (or expected) mass. x 100 The reaction to be studied is the double displacement reaction between sodium bicarbonate (NaHCO3), commonly known as baking soda, and hydrochloric acid (HCl). The reaction produces table salt or sodium chloride (NaCl) and carbonic acid (H2CO3). The carbonic acid readily decomposes to water and carbon dioxide as shown by the equations below. NaHCO3 + HCl → NaCl + H2CO3 NaHCO3 + HCl → NaCl + H2O + CO2 A known mass of NaHCO3 will be reacted completely with an excess of HCl. From the actual mass of sodium chloride produced and the calculated theoretical yield, the percent yield of the reaction can be determined. Pre-Lab Questions: (Write your answers on a separate sheet of paper. Turn in Pre-Lab paper the day before the lab) A sample of silver oxide (Ag2O) was heated several times to drive out all of the oxygen, leaving behind silver, according to the reaction, 2Ag2O → 4Ag + O2 The following data were collected. Mass of crucible (g) 20.5552 Mass of crucible + Ag2O (g) 22.5535 Mass of crucible + remaining solid after first heating (g) 22.38220 Mass of beaker + remaining solid after second heating (g) 22.1621 Mass of beaker + remaining solid after third heating (g) 22.1621 (1) How many grams of silver oxide (Ag2O) was used in the reaction? (2) How many grams of the solid (Ag) remained after the third heating? (3) How many grams of Ag are expected to be produced from the grams of silver oxide used in the reaction? (4) Calculate the percent yield of the reaction. Materials: 250-mL beaker, weighing paper, spoon, dropper, hot plate, baking soda (NaHCO3) and hydrochloric acid (HCl). Procedure: 1. Weigh an empty beaker. 2. Place about 1 g of NaHCO3 into the beaker. Record the mass of the beaker and the NaHCO3. 3. Add HCl to NaHCO3 drop by drop. When the reaction mixture stops fizzing all of the NaHCO3 has been reacted. 4. Gently heat the beaker on a hot plate until all the liquid has evaporated. 5. Carefully take the beaker off the hot plate. Allow it to cool and take the mass of the beaker and the salt that is left in the beaker. 6. Repeat steps 4-5 until no more decrease in mass is observed. Data: Mass of empty beaker (g) Mass of beaker + NaHCO3 (g) Mass of beaker + NaCl after first heating (g) Mass of beaker + NaCl after second heating (g) Mass of beaker + NaCl after third heating (g) Calculation: 1. Calculate the mass of the NaHCO3 used in the reaction. 2. Calculate the mass of NaCl actually produced from the reaction. 3. Calculate the theoretical yield of the reaction, that is, the mass in grams of NaCl that is expected to be produced from mass of NaHCO3 used in the reaction. 4. Calculate the percent yield of the reaction Analysis: Why was the NaCl produced from the reaction heated several times? How does the actual yield compare to the theoretical yield? List 3 possible sources of error in the experiment and explain how these errors affected the result. (Be specific!) Conclusion: What was the purpose of the experiment? Was this purpose achieved? What have you learned from the experiment? Day 25, 26, 27 Review – Benchmark Assessment and Finals PowerPoints are attached. Review may be done using a Cooperative Learning strategy called Numbered-Heads-Together. Students working in groups of 3 figure out answer to each question together. Group member whose number is called writes the answer on white board for teacher to check. Slide 1 Slide 7 NH3 + HCl → NH4Cl How many grams of NH3 are needed to produce 25 g of ammonium chloride? Test Review Chemical Reactions and Stoichiometry Slide 2 8.0 g NH3 Slide 8 2NH3 → N2 + 3H2 This test includes: 1. identifying types of reactions 2. writing and balancing of equations 3. calculation of moles, mass and volume of reactants and products. 4. calculation of the % yield of a reaction. How many moles of NH3 are needed to produce 2.0 g of hydrogen? 0.67 moles NH3 Slide 3 Slide 9 CaCO3 → CaO + CO2 Propane reacts with oxygen to produce water and carbon dioxide based on the equation: Which is true of the above reaction? C3H8 + A. Calcium oxide and carbon dioxide are reactants. B. The reaction involves the decomposition of calcium carbonate. C. The reaction involves the combination of calcium oxide and carbon dioxide. D. The reaction involves the combustion of calcium carbonate. 5O2 → 4H2O + 3CO2 What volume of propane at STP is needed to produce 6.0 moles of CO2? 44.8 L B Slide 4 Slide 10 Which is a single displacement reaction? A. NH4NO2 → N2 + 2H2O B. Na2SO4 + Ba(NO3)2 → BaSO4 + 2NaNO3 C. Fe + 2HCl → FeCl2 + H2 D. C2H5OH + 3O2 → 2CO2 + 3H2O Propane reacts with oxygen to produce water and carbon dioxide based on the equation: C3H8 + 5O2 → 4H2O + 3CO2 How many grams of oxygen gas are needed to completely burn 22.4 L of propane at STP? 160 g C Slide 5 Slide 2H2O → 2H2 + O2 11 Which of these equations is balanced? A. NH4NO2 → N2 + H2O B. NH3 + HCl → NH4Cl C. 2NH3 → N2 + H2 D. NH4NO3 → N2O + H2O B 1. How many grams of oxygen can be formed from the decomposition of 36 g of water? 2. If only 30 g of oxygen is actually produced from 36 g of water, what is the % yield of the reaction? 32 g O2, 94% Slide 6 NH3 + HCl → NH4Cl How many moles of hydrogen chloride are needed to produce 0.35 moles of ammonium chloride? 0.35 moles HCl Slide 12 4Al+ 3O2 → 2Al2O3 100.0 g of Al and 100.0 g of O2 react. What are the limiting and excess reactants? How many grams of Al2O3 are produced? Limiting: Al Excess: O2 188.9 g Al2O3 Slide 1 Slide 6 Calculate the % error of a measurement (0.90 g/mL) if the true value is 1.0 g/mL. Answer: 10% Final Exam Review Chemistry – First Semester Slide 2 “Matter is made up of atoms. Atoms have tiny positive centers containing protons and neutrons.” Slide 7 The above statement is a/an A. inference B. hypothesis C. theory D. observation Answer: C Which of these statements is NOT true about matter and energy? A. All matter possesses energy. B. Matter can be changed into energy and energy can be changed into matter. C. Energy can only be transferred from one sample of matter to another when they are in direct contact with one another. D. The total amount of matter and energy in the universe remains the same; they just change from one form to another. Answer: C Slide 3 In order to become a theory, a hypothesis should be A. obviously accepted by most people. B. a fully functional experiment. C. in alignment with past theories. D. repeatedly confirmed by experimentation Slide 8 Answer: D Which of these is an exothermic process? A. Melting of ice B. Combustion (burning) of gasoline C. Photosynthesis D. Evaporation of water Answer: B Slide 4 Slide 5 What is the density of a substance which has a volume of 100.0 mL and a mass of 85.5 g? Answer: 0.855 g/mL How many significant digits does this measurement have? 95.50 mL Answer: 4 Slide 9 Slide 10 An endothermic reaction A. releases energy to the surroundings. B. causes a temperature increase in its surroundings. C. absorbs energy from its surroundings. D. produces substances that have a lesser energy than the starting materials. Answer: C Which is true about metals? A. They are found on the right side of the periodic table. B. They are poor conductors . C. They have higher densities compared to non-metals. D. Most of them are liquids and gases at room temperature. Answer: C Slide 11 A. B. C. D. The nucleus of an atom is negatively-charged accounts for most of the atom’s mass occupies most of the atom’s volume contains electrons and protons Slide 16 When a metal is heated in a flame, the flame turns a distinctive color. This information can be applied in the study of stars because A. star color tells us how far it is from the earth. B. the color of the star tells us how big it is. C. the color of the star tell us how old it is. D. the color spectra of a star show which elements are present in it. Answer: D Answer: B Slide 12 Give the number of protons, electrons and neutrons of 158O. Slide 17 How many valence electrons does nitrogen have? Answer: electrons- 8, protons- 8, neutron-7 Slide 13 Which of these is NOT true of the atom? A. It may be positively or negativelycharged. B. It contains the same number of protons and electrons. C. It is mostly empty space. D. It has a very dense center. Answer: 5 Slide 18 Draw the Lewis Dot diagram of carbon Answer: C Answer: A Slide 14 Isotopes of the same element always have the same A. atomic number B. mass number C. atomic mass D. number of neutrons Slide 19 Which element do you expect to have the same valence electrons as carbon? A. B. C. D. Answer: A calcium iron chlorine silicon Answer: D Slide 15 Some isotopes easily break down and emit radiation. Which type of radiation is the least penetrating? A. beta B. alpha C. X-ray D. gamma Answer: B Slide 20 Write the electron configuration of potassium. Answer: 1s2 2s2 2p6 3s2 3p6 4s1 Slide 21 Slide 22 Slide 23 Which of these is a halogen? A. helium B. carbon C. lithium D. iodine Answer: D To which family does the element krypton belong? A. Alkali metal B. Alkaline-earth metal C. Transition Metal D. Noble gases Answer: D Which of these is true of noble gases? A. They have 8 valence electrons except for helium. B. They belong to Group 2A. C. They easily form bonds with other elements. D. They have very low ionization energies. Answer: A Slide 26 Which element is the least electronegative? A. Nitrogen B. Phosphorus C. Oxygen D. Sulfur Answer: B Slide 27 Which type of chemical bond exists between a metal and a non-metal? Ionic Slide 28 Answer: A Slide 24 Slide 25 In general, how do atomic masses change throughout the periodic table of elements? A. They increase from left to right and top to bottom. B. They increase from left to right and bottom to top. C. They increase from right to left and top to bottom. D. They increase from right to left and bottom to top. Answer: A Why is cobalt (Co) placed before nickel (Ni) on the periodic table even though its atomic mass is higher than nickel’s? A. Cobalt has more electrons. B. Nickel has a higher density. C. Cobalt was discovered first. D. Nickel has one more proton. Answer: D Slide 29 Metallic substances are usually good conductors of electricity because A. of the loosely bonded electrons that move around the metal structure B. of the closely packed atoms C. of the strong bonds that exist between atoms D. of the weak bonds that exist between atoms Answer: A Slide 30 Which of these is NOT an electrical conductor? A. aluminum B. Alcohol (C2H5OH) solution C. Potassium chloride (KCl) solution D. Hydrochloric acid (HCl) solution Answer: B Slide 31 Slide 32 Which element can form long chains of atoms by forming single, double and triple bonds with itself? A. oxygen B. nitrogen C. carbon D. hydrogen Answer: C What is the correct formula of sodium bromide? A. NaBr B. Na2Br C. NaBr2 D. Na2Br2 Answer: A Slide 33 Slide 36 Give the name of FeSO4 Iron (II) sulfate Slide 37 What is the correct formula of sodium bromide? A. NaBr B. Na2Br C. NaBr2 D. Na2Br2 Answer: A Slide 38 Which of these is an acid? H2SO4 KOH K2SO4 What is the chemical formula for sodium sulfate? Na2SO4 Answer: H2SO4 Slide 34 Slide 39 What is the chemical formula for copper (II) nitrate? Which is a polar covalent bond? A. N-H B. As-H C. O-O D. Cl-Cl Cu(NO3)2 A Slide 35 Slide 40 Give the name of CaCl2 Write the Lewis dot diagram of H2S. Calcium Chloride H S H Slide 41 Slide 46 How many non-bonding (unshared) pairs of electrons does sulfur have in H2S? Predict the shape of the NH3. 2 Trigonal Pyramidal Slide 42 Slide 47 These pairs of atoms are covalently bonded. Arrange them according to increasing polarity. A. N-O B. Cl-F C. C-H D. C-Cl How many non-bonding pairs does sulfur have in H2S? 2 Slide 43 C,D,A,B Slide 48 Which of these is an alkene? A. C3H8 B. C4H8 C. C5H8 D. C6H14 What is the shape of the H2S molecule? Bent Slide 44 B Slide 49 Is the H2S molecule polar or nonpolar? Polar B Slide 45 Slide 50 NH3 + HCl → NH4Cl Which of these is a polar molecule? A. CO2 B. SF6 C. CH4 D. PCl3 How many grams of NH3 is needed to produce 25 g of NH4Cl? 8.0 g of NH3 D Day 28, 29, 30 Benchmark Assessment 3 Final Exams