Download Semester 2 Review WS

Chemistry – Review for Final Exam
Measurement and Calculations:
1. Demonstrate understanding of the use of measurements in science.
Express the answer in the correct number of significant figures. Label with appropriate units.
CALCULATOR ANSWER (WITH
CORRECT UNITS)
CALCULATION
ANSWER ROUNDED TO
CORRECT # OF SIG FIGS
21.3 g
1.3 cm3
6.34 cm2 x 1.2 cm
1.217 cm
13.21 m x 61.5 m
21.50 cm
8.50 in
2. You should also be able to measure the length of an object or volume of a liquid to the appropriate
number of significant figures based upon the measuring instrument.
a. What answer best expresses the length of the
object drawn below? Circle your answer.
a. 2 cm
b. 2.4 cm
c. 2.45 cm
b. What answer best expresses the volume of the
water in the graduated cylinder below.
Circle your answer.
d. 2.50 cm
a. 43 mL
b. 43.0 mL
c. 40 mL
d. 44.0 mL
3. Demonstrate proficiency in the use of proportions in metric conversions. Know the meaning of the
following metric prefixes and be able to make conversions utilizing them: milli-, centi-, kilo-.
Complete the indicated conversions:
a. 37 g =
b. 4.7 kg =
mg
g
c. 2.1 x 10-3 kL = _____________ mL
d. 138 m =
km
e. 4021 mm =
m
4. Be able to convert standard notation to scientific notation and vice versa.
Standard Notation
Scientific Notation
1300
0.00155
1.68 x 106
2.73 x 10-2
Matter and Atomic Theory
1. Use the picture below to answer the questions that follow.
a.
What is represented in Figure A?
b. Does Figure B represent a compound or an element? Explain how you know.
c.
Which diagrams show only molecules? ___________________________________________
How are these pictures different from one another?
d. What is represented in letter C? _________________________________________________
e. How many total ATOMS are there in letter D? _____________________________________
f. How many total MOLECULES are there in letter D? ________________________________
2. Distinguish between the structure of molecular and ionic solids. What is different about how they are
named?
3. Given the formula of a compound, identify the number of each type of atom present.
Identify the number of atoms/ions of each kind in each compound.
- Pb(NO3)2 : ______ lead atoms, ______ nitrogen atoms, _______ oxygen atoms
- Na3PO4 :
______ sodium ions, _______ phosphate ions
- Al2(SO4)3 : ______ TOTAL ions, ______ TOTAL atoms
4. Name ionic and molecular compounds from formulas and vice versa.
Write the formula of the following compounds. Circle the ionic compounds! Underline polyatomic ions.
a potassium iodide
l. manganese (III) hydroxide _____________
b. nitrogen dioxide
m. carbon tetrachloride __________________
c.
sodium oxide
n. copper (I) sulfide ____________________
d. aluminum chloride
o. calcium nitrate _______________________
e.
tin (IV) chloride
p. potassium phosphate __________________
f.
iron (III) sulfide
q. aluminum acetate _____________________
g.
carbon diselenide
r. ammonium sulfate ____________________
h. ammonium chloride
__________________ s. lead (IV) sulfite ______________________
i. diphosphorus pentoxide _________________ t. magnesium bromide __________________
j. nickel (II) oxide
__________________ u. aluminum chlorate ___________________
k. zinc chlorate
__________________ v. potassium permanganate
_______________
Write the name of the following compounds. Circle the ionic compounds! Underline polyatomic ions.
a. SnO
j. CuO
b. PbBr4
k. P2O5
c. SO2
l. KOH
d. Al2O3
m. Mg(ClO3)2
e. Cr(ClO2)2
n. Ag2SO4
f. CaO
o. Mn2(SO4)3
g. Al(OH)3
p. Pb(NO3)2
h. Cu2SO4
i. (NH4)2CO3
q. CCl4
r. NaHCO3
5. Conductivity of molecular and ionic compounds
a. Draw particle diagrams to show the following:
PbBr4 as a solid
PbBr4 dissolved in water
CCl4 as a solid
CCl4 dissolved in water
b. Identify the molecular compound and the ionic compound. Explain how you know this.
c. Which compound (and in what form) will conduct electricity and which will not. Explain why.
The mole concept and chemical reactions
Recognize that atoms are too small to count directly. We determine how many there are in a sample by
finding their mass. We use the mole to determine the number of atoms and molecules. Molar mass (on
Periodic Table) is relative mass, based originally on hydrogen (lightest element) and now on 1/12 of C-12.
1.
Be able to determine the molar mass of a compound.
Determine the molar masses of the following compounds.
a.) Pb(NO3)2
b.) BaSO4
c.) Potassium sulfate
d.) Iron (III) hydroxide
2. Be able to make conversions between moles, grams, and number of particles using proportions.
Complete the following problems.
a. How many moles are in 12.0 grams of MgCl2?
b. How many molecules are there in 3.50 moles of CO2?
c. How many molecules are there in 22.4 grams of water?
d. What is the mass of 5.82 x 1018 molecules of MgO?
e. How many chloride ions are there in 4.60 moles of calcium chloride?
3. Determine the empirical and/or molecular formulas using data.
a.) What is the empirical formula of a compound containing 24.74 g of potassium, 34.76 g of
manganese, and 40.50 g of oxygen.
b.) What is the empirical formula of a compound containing 3.611 g of calcium and 6.389 g of chlorine?
c.) Determine the empirical and molecular formulas of a compound that contains 30.45 g of nitrogen and
69.55 g of oxygen. The molar mass of the compound is 92.02 g/mole.
d.) Determine the molecular formula of a compound that contains 56.36% of oxygen and 43.64% of
phosphorus. The molar mass of the compound is 283.9 g/mole.
4. Be able to represent a balanced chemical equation.
a. Balance and draw particle diagrams to represent the following equations:
_____ Ba
+
_____ HCl
_____ HNO3
+ _____ Ba(OH)2
_____ BaCl2
+
_____ H2
_____ Ba(NO3)2 + _____ H2O
5. Write the balanced equations and the type of reaction for the examples below. (remember diatomics!)
Synthesis (S), Decomposition (D), Single replacement (SR), Double replacement (DR), or Combustion (C).
a. Barium chlorate, when heated, produces barium chloride and oxygen gas. TYPE:___
b. Ethane, C2H6, burns in air to produce carbon dioxide and water. TYPE:___
c. Lime, (calcium oxide) reacts with sulfur dioxide to form calcium sulfite. TYPE:____
d. Chromium reacts with oxygen gas to produce chromium (III) oxide. TYPE:_____
e. Aluminum bromide reacts with chlorine gas to produce aluminum chloride and liquid bromine. Type:____
f. Nickel (II) nitrate reacts with sodium hydroxide to form nickel (II) hydroxide and sodium nitrate.
TYPE:___
6. For the following reactions, write the word ENERGY on the correct side of the balanced equation.
a. When sulfur (S8) reacts with silver metal, silver sulfide forms and the container feels hot.
b. When nickel (II) chlorate is heated, it breaks down into nickel (II) chloride and oxygen gas.
c. Sodium bicarbonate breaks down to form sodium carbonate, carbon dioxide, and water vapor. This is
an example of an exothermic reaction.
d. Zinc sulfide reacts with oxygen gas to form zinc oxide and sulfur dioxide. This is an example of an
endothermic reaction.
7. Demonstrate knowledge that matter is conserved in ordinary chemical reactions.
Example: If 3.6 g of water is decomposed, what mass of hydrogen will be produced if 3.2 g of oxygen is
produced?
8. Use a balanced equation to predict the quantity of reactant or product involved in a chemical reaction.
(Show your BCA table)
a.) Calculate the number of grams of potassium chloride, KCl, that will be formed by the decomposition of
6.45 g of potassium chlorate, KClO3.
BEFORE
CHANGE
AFTER
b.) Phosphorus and bromine react vigorously together to form phosphorus tribromide. If 8.50 grams of
phosphorus and 62.0 grams of bromine react, how many grams of phosphorus tribromide should be
produced?
BEFORE
CHANGE
AFTER
9. Determine percent yield when actual yield is known.
a.) A chemist burns 160. g of Al in air to produce 260. g of solid aluminum oxide. Determine the
theoretical yield. Determine the percent yield.
BEFORE
CHANGE
AFTER
b.) When hydrochloric acid is added to sodium bicarbonate, it produces water, sodium chloride and carbon
dioxide. If 20.0 grams of sodium bicarbonate reacts and 6.75 g of CO2 is produced, what is the percent yield
of the carbon dioxide?
BEFORE
CHANGE
AFTER
10. Use the limiting reactant to predict amount of product formed.
a.) How many grams of water can be formed when 28.7 g of CH4 reacts with 45.8 g of O2?
The unbalanced reaction is:
_____ CH4 +
_____ O2
_____ CO2 + _____H2O
BEFORE
CHANGE
AFTER
b.) Zinc sulfide and oxygen gas react to form zinc oxide and sulfur dioxide. If 72.3 grams of ZnS
react with 24.6 grams of oxygen, what is the limiting reactant? What is the mass of the leftover
excess reactant?
BEFORE
CHANGE
AFTER
11. From a representation of a reaction mixture before and after the reaction, determine the balanced
equation for a reaction.
Balanced equation:
12. Use the following lab data to answer the questions below.
A student places a piece of magnesium into aqueous hydrochloric acid (HCl). Magnesium chloride forms in
the bottom of the beaker and hydrogen gas bubbles away. The beaker was set aside so that the reaction
completely finished and all water evaporated away. This data was obtained:
Mass of beaker:
124.52 g
Mass of Mg before reaction:
4.45 g
Mass of Mg present after reaction:
1.12 g
Mass of beaker and dry magnesium chloride: 135.77 g
Using the information above, determine the percent yield of magnesium chloride. SHOW ALL WORK
INCLUDING A BCA TABLE BELOW!