Download Review Session Handout from 10/6

Kylie’s Review October 6, 2005
1. How many moles of solute are present in the following solutions:
(a) 65.0 mL of 0.125 M HNO3?
(b) 120.0 mL of 1.500 M NaCl?
2. How many grams of solute are required to prepare the following solutions:
(a) 100.0 mL of 0.400 M H3BO3?
(b) 500.0 mL of 1.20 M HCl?
3. How many moles of Cl- ions are present in 25.0 mL of 1.4 M CaCl2?
4. How many moles of K+ ions are present in 150.0 mL of 0.850 M KNO3?
5. How many Li+ ions are present in 250.0 mL of 2.0 M Li3PO4?
6. How many NO3- ions are present in 500.0 mL of 0.750 M Ca(NO3)2?
7. How many total moles of ions are present in 100.0 mL of 4.5 M Cu(NO3)2?
8. How many total moles of ions are present in 175.0 mL of 0.950 M NaOH?
9. The concentration of glucose (C6H12O6) in the blood is 90 mg per 100 mL. What is the molarity of the glucose?
10. A bottle of 12.0 M HCl has only 35.7 mL left in it. What will the concentration of the HCl be if the solution is diluted to
250.0 mL?
11. What is the volume of a solution that would result by diluting 70.00 mL of 0.0913 M NaOH to a concentration of
0.0150M?
12. A flask containing 450. mL of 0.500 M HBr was accidentally knocked onto the floor. How many grams of K 2CO3 would
you need to neutralize the spill?
2HBr (aq) + K2CO3 (aq)  2KBr (aq) + CO2(g) + H2O(l)
13. The odor of skunks is caused by chemical compounds called thiols. These compounds, of which butanethiol (C 4H10S) is
a representative example, can be deodorized by reaction with household bleach (NaOCl) according to the following
reaction:
2C4H10S + NaOCl(aq)  C8H18S2 + NaCl(aq) + H2O(aq)
How many grams of C4H10S can be deodorized by reaction with 5.00 mL of 0.0985 M NaOCl?
Neutralization Reactions
14. Oxalic acid, H2C2O4, is a toxic substance found in spinach leaves, what is the molarity of a solution made by dissolving
12.0 g of oxalic acid in enough water to give 400.0 mL of solution? How many mL of 0.100 M KOH would you need to titrate
25.0 mL of the oxalic acid solution according to the following reaction:
H2C2O4(aq) + 2KOH(aq)  K2C2O4(aq) + 2H2O(l)
15. How many mL of 1.8 M H2SO4 are required to neutralize 75.0 mL of 0.750 M KOH?
H2SO4(aq) + 2KOH(aq)  2H2O(l) + K2SO4(aq)
16. How many mL of 0.200 M LiOH are required to neutralize 17.50 mL of 1.0 M HClO4?
HClO4(aq) + LiOH (aq)  LiClO4(aq) + H2O(l)
17. For the reaction: HNO3(aq) + NaOH(aq)  NaNO3(aq) + H2O(l)
12.75 mL of 0.950 M HNO3 are titrated with 19.50 mL of NaOH. What is the concentration of the base?
18. For the reaction: Mg(OH)2 (aq) + 2HBr (aq)  MgBr2 + 2H2O (l)
How many mL of 0.250 M HBr are required for the titration of 17.55 mL of 0.100 M Mg(OH)2?
Reaction Practice
19. ___Ba(NO3)2 (aq) + ___Na2SO4(aq)  ___________ + ___________
Ionic Eqn___________________________________________________________________________
Net Ionic Eqn________________________________________________________________________
20. ___KCl (aq) + ___AgNO3 (aq)  __________ + ___________
Ionic Eqn___________________________________________________________________________
Net Ionic Eqn________________________________________________________________________
21. ___H2SO4 (aq) + ___LiOH (aq)  ___________ + ___________
Ionic Eqn___________________________________________________________________________
Net Ionic____________________________________________________________________________
22. ___HI(aq) + ___Ca(OH)2 (aq)  ___________ + _____________
Ionic Eqn___________________________________________________________________________
Net Ionic Eqn________________________________________________________________________
Redox Test-type problem (from last spring’s exam)
23. Metallic gold can be prepared by treating an aqueous solution of gold cations with and aqueous solution of iodide anions. Balance
the following equation using oxidation numbers.
_____Au3+ (aq) + _____I- (aq) → _____Au (s) + _____I2 (s)
(b) What is the reducing agent in the equation above? _____
(c) How many total electrons are exchanged in the balanced equation? _____
(d) What is the oxidation number of I2 in the equation above? _____
(e) What is the oxidation number of phosphorous in H3PO4? _____
Simple Pressure Problems
24. How many moles of methane gas, CH4, are in a storage tank with a volume of 1.000x105 L at STP? How many grams?
25. An aerosol spray can with a volume of 350 mL contains 3.2 g of propane gas, C3H8, as a propellant. What is the
pressure (in atm) of the gas in the can at 20C?
26. A helium gas cylinder of the sort used to fill balloons has a volume of 43.8 L and a pressure of 1.35 atm at 25C. How
many moles of helium are in the tank?
27. How many moles of air are in the lungs of an average adult with a lung capacity of 3.8 L? Assume that the person is at
1.00 atm and has a normal body temperature of 37C.
Gas Undergoing a Change
28. In a typical automobile engine, the mixture of gasoline and air in a cylinder is compressed from 1.0 atm to 9.5 atm. If
the uncompressed volume of the cylinder is 410 mL, what is the volume (in mL) when the mixture is fully compressed?
29. What final temperature (in C) is required for the pressure inside an automobile tire to increase from 2.15 atm at 0C to
2.37 atm, assuming the volume remains constant?
30. 15.0 g of CO2 gas is stored in a 750 mL steel container at 1.15 atm and 19C. What is the pressure if the container is
heated to 95C?
Gas Density and MM Determination
31. What is the density (in g/L) of ammonia gas at 25C and 733.4 mm Hg pressure?
32. To identify the contents of an unlabeled cylinder of gas, a sample was collected and found to have a density of 5.380
g/L at 15C and 736 mm Hg pressure. What is the molar mass of the gas?
Gas Stoichiometry & Limiting Reactants
33. Carbonate-bearing rocks like limestone (CaCO3) react with dilute acids such as HCl to produce CO2, according to the
reaction:
CaCO3 (s) + 2HCl(aq)  CaCl2(aq) + CO2 (g) + H2O(l)
How many grams of CO2 are formed in the reaction of 33.7 g of CaCO3 with 10.0mL of 0.350M HCl? What is the volume (in
liters) ot this CO2 at STP?
34. Propane gas, C3H8, is used as a fuel in rural areas. How many grams of CO2 are formed if 1.9 g of C3H8 are allowed to
react with 3.5 L of O2 at 32.5C and 735 mm Hg? C3H8(g) + 5O2(g)  3CO2(g) + 4H2O(l)
35. How many moles of O2 are formed from the reaction of 3.25 g of Na2O2 and 1.75L of CO2 at 1.15 atm and 38C?
2Na2O2 (s) + 2CO2(g)  2Na2CO3(s) + O2 (g)
36. (from last spring’s exam) Margarine can be made from natural oils such as coconut oil by hydrogenation:
C57H104O6 (l) + 3 H2 (g) → C57H110O6 (s)
If an industrial hydrogenator with a volume of 2.50 x 102 L is filled with 12.0 kg of oil (C57H104O6) and 7.00 atm of H2 at 473
K, how many kilograms of margarine will be produced?
(molar mass C57H104O6 = 885.443 g/mol; molar mass H2 = 2.0158 g/mol; molar mass C57H110O6 = 891.490 g/mol)
Collecting a Gas Over Water
37. 222 mL of hydrogen gas is collected over water in the following reaction: Ca(s) + 2H 2O(l)  H2(g) + Ca(OH)2(aq)
If the temperature is 20.0C and atmospheric pressure is 745 torr, how many moles of hydrogen gas are collected?
37. (from last spring’s exam) During the decomposition of KClO3, 92.00 mL of O2 is collected by displacement of water at 25 C. If
atmospheric pressure is 756 mm Hg, what mass of O2 is collected? 2 KClO3 (s) → 3 O2 (g) + 2 KCl (s)
38. 0.750 g of Mg is reacted with 25.0 g H2O Mg(s) + H2O(l)  Mg(OH)2(aq) + H2(g)
If the H2 is collected over water, what is the total volume that could be produced if the experiment was done at 25 C and
750 torr?
Heat, Kinetic Energy, & Rates
38. An iron kettle weighing 1.35 kg contains 2.75 kg of water at 23.0 C. The kettle and the water are heated to 95C. How many
joules of energy are absorbed by the water and by the kettle?
39. A dish containing 145 g of water at 54.0C is put in a refrigerator to cool. It is removed when its temperature is 5.50C. What is q
for the water?
40. A piece of silver whose mass is 15.0 g is immersed in 25.0 g of water. This system is heated electrically from 24.0 to 37.6C. How
many joules of energy are absorbed by the water, and how many by the silver?
41. Calculate the kinetic energy of a 255 g chemistry text book that is moving at 2.0 m/s.
42. Calculate the speed of an object that has a mass of 12.0 g and a kinetic energy of 212 J.