* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Name: ______KEY__________________ Date: ______ CHM 130
Biochemistry wikipedia , lookup
Water splitting wikipedia , lookup
Hydrogen-bond catalysis wikipedia , lookup
List of phenyltropanes wikipedia , lookup
Acid dissociation constant wikipedia , lookup
Catalytic reforming wikipedia , lookup
Liquid–liquid extraction wikipedia , lookup
Acid–base reaction wikipedia , lookup
Hydrogen bond wikipedia , lookup
Gas chromatography wikipedia , lookup
Self-assembled monolayer wikipedia , lookup
Molecular dynamics wikipedia , lookup
Atomic theory wikipedia , lookup
Diamond anvil cell wikipedia , lookup
Chemical bond wikipedia , lookup
Size-exclusion chromatography wikipedia , lookup
History of molecular theory wikipedia , lookup
Crystallization wikipedia , lookup
Hypervalent molecule wikipedia , lookup
Implicit solvation wikipedia , lookup
Gas chromatography–mass spectrometry wikipedia , lookup
Thermometric titration wikipedia , lookup
Organosulfur compounds wikipedia , lookup
Electrolysis of water wikipedia , lookup
Bioorthogonal chemistry wikipedia , lookup
Geometrical frustration wikipedia , lookup
Name: ______KEY__________________ Date: ________ CHM 130, Exam 3: Chapters 9, 10, 11, and 13 (and some of 14) Show all work and clearly mark all answers for full credit. 16. (4 pts) “Joe” decides to throw 3.45 grams of solid sodium into a “friend’s” pool. How many moles of sodium is this? 3.45 g Na x (1 mol / 22.99 g) = 0.150 mol Na 17. (6 pts) Calculate the grams of CO2 in an 79.8 liter container at STP. 79.8 L x (1 mol / 22.4 L) x (44.01 g / 1 mol) = 157 g CO2 18. (3 pts) Calculate the percent composition of aluminum in aluminum oxide (Al2O3). Al: 2 x 26.98 = 53.96 O: 3 x 16.00 = 48.00 % Al = (mass of Al / total mass) x 100 % Al = (53.96 / 101.06) x 100 = 52.92 % Total mass = 101.96 g/mol _A__ 19. (4 pts) In the reaction P4 + 5 O2 2 P2O5, how many moles of diphosphorus pentoxide are produced when 0.500 moles of O2 are used? a. 0.200 mol b. 0.500 mol c. 1.25 mol d. 2.50 mol e. 5.00 mol 0.500 mol O2 x (2 mol P2O5 / 5 mol O2) = 0.200 mol P2O5 20. (8 pts) Silver nitrate and sodium sulfate solutions react to make silver chloride and sodium nitrate according to the balanced equation below. How many grams of silver nitrate are needed to completely react with 0.327 grams of sodium sulfate? 2 AgNO3 (aq) + Na2SO4 (aq) Ag2SO4 (s) + 2 NaNO3 (aq) 0.327 g Na2SO4 x (1 mol Na2SO4 / 142.05 g) x (2 mol AgNO3 / 1 mol Na2SO4) x (169.88 g AgNO3 / 1 mol) = 0.782 g AgNO3 _E__ 1. (5 pts) Which of the following describes properties of gases? a. They are compressible. b. They expand to fill a container. c. They take the shape of a container. d. The particles in a gas are far apart. e. All of the above are true. CHM 130, Leedy Spring 2013 page 1 of 4 Name: ______KEY__________________ 2. (6 pts) Convert 694 torr to units of a) atm, b) mmHg, and c) psi. Date: ________ a. atm: 694 torr x (1 atm / 760 torr) = 0.913 atm b. mm Hg: 694 torr x (760 mm Hg / 760 torr) = 694 mm Hg c. psi:694 torr x (14.7 psi / 760 torr) = 13.4 psi 3. (6 pts) You have a 1.00 L bottle of gas (closed), with P = 0.444 atm and T = 295° C. If you raise the temperature to 395oC, will the pressure increase or decrease (circle one)? Calculate the new pressure. P1 / T1 = P2 / T2; 0.444 atm / (295 + 273) = P2 / (395 + 273) P2 = 0.522 atm 4. (6 pts) A sample of helium at 35oC, a volume of 0.25 L, and a pressure of 515 mm Hg is compressed to a volume of 0.50 L, will the pressure increase or decrease (circle one)? Calculate the final pressure. Use Boyle’s Law for a constant temperature case of the ideal gas law: P1V1 = P2V2 P2 = (515 mmHg)(0.25 L) / ( 0.50 L ) P2 = 260 mm Hg (or 0.34 atm) 5. (6 pts) A 6.35 L sample of carbon monoxide is collected at 55oC and 0.892 atm. What volume will the gas occupy at 1.05 atm and 21oC? P1V1 / T1 = P2 V2 / T2 (0.892 atm * 6.35 L) / (55 + 273) = (1.05 atm * x ) / (21 + 273) 0.0172689 = 0.0035714 x x = 4.85 L (3 or 4 sig figs) 6. (12 pts) True or False: Circle the appropriate letter for each statement below: a. T F Liquids have a constant shape and constant volume. b. T F London forces are the strongest type of intermolecular force. c. T F Intermolecular forces holding molecules together are weaker than chemical bonds. d. T F Nonpolar molecules will have Dipole-Dipole forces. e. T F Xe is predicted to have higher a boiling point than He. f. T F CHM 130, Leedy H2 is predicted to have a higher vapor pressure than H2O. Spring 2013 page 2 of 4 Name: ______KEY__________________ Date: ________ 7. (4 pts) What is the strongest type of intermolecular force (London forces, Dipole-Dipole, or Hydrogen Bond Forces) in: CH4: ___London forces___ H2O: ___Hydrogen Bond Forces______ 8. (4 pts) Use the intermolecular force types of CH4 and H2O from the question above to determine the following properties below. a. Higher vapor pressure: __CH4___ b. Higher boiling point: __ H2O ____ c. Stronger surface tension: __H2O__ d. Higher viscosity: __ H2O ___ 9. (6 pts) What holds the following together? Your choices are nonpolar covalent bond (NPC), polar covalent bond (PC), ionic bond (I), London forces (LDF), Dipole-Dipole forces (DD), and Hydrogen Bond Forces (HBF). a. __PC_ N and O atoms in NO2. b. _HBF_ The molecules in ammonia. c. _NPC_ Chlorine atoms in Cl2. d. __I__ Li and Cl ions in a solid. e. _LDF_ Cl2 molecules in a gas. f. _DD__ Two CH2F2 molecules. _A__ 10. (5 pts) Which one of the following is an example of a metallic solid? a. Mg (s) b. CaCl2 (s) c. CO2 (s) d. P4 (s) 11. (6 pts) The graph to the right represents a temperature versus heat energy plot for a pure substance. Answer the following questions. a. What letter represents pure gas? _E___ b. What phase changes occur at letter B? __melting/freezing___________ c. What is the temperature of the boiling point of this substance? __60oC_____ d. What letter represents pure solid? _A__ 12. (8 pts) Complete the following table by determining if each solute will or will not mix with each solvent. Your choices for each combination are miscible, immiscible, soluble, or insoluble. Solvents () ZnSO4 (s) CH2F2 (l) S8 (s) Br2 (l) H2O (l) soluble miscible insoluble immiscible CCl4 (l) insoluble immiscible soluble miscible CHM 130, Leedy Spring 2013 page 3 of 4 Name: ______KEY__________________ __C_ 13. a. b. c. d. Date: ________ (5 pts) A nitric acid solution that is 70.0% HNO3 by mass contains 70.0 g of HNO3 and 100.0 g water. 70.0 mol HNO3. 70.0 g HNO3 and 30.0 g water. 70.0 g HNO3 and 70.0 g water. 14. (5 pts) An oven cleaning solution is 40.0 % by mass of NaOH. If one jar of this product contains 454 grams of solution, how many grams of NaOH does it contain? Show all work. Mass solute / mass solution x 100 = (x g / 454 g) x 100 = 40.0% x = 454 g * 0.400 = 181.6 g = 182 g 15. (5 pts) If 160.20 grams of NH4Cl is dissolved in 4.00 L of water, what is the concentration (molarity) of the solution? 160.20 g x (1 mol / 53.5 g) = 2.994 mol NH4Cl / 4.00 L = 0.749 M _C__16. (5 pts) What is the term for a substance that donates a proton in an acid-base reaction? a. Arrhenius acid b. Arrhenius base c. Bronsted-Lowry acid d. Bronsted-Lowry base 17. (2 pts) In the following reaction, which reactant is a Bronsted-Lowry base? Circle your answer. NH3(aq) + H2O (l) NH4+ (aq) + OH- (aq) 18. (4 pts) What is the pH of a solution with [H+] = 1.0 x 10-3 M? __3.0____________ Is this solution acidic, basic, or neutral? ___acidic__________ CHM 130, Leedy Spring 2013 page 4 of 4