Workshop CHE 166
Problem Set #6
1. According to the equation CH4 (g) + 2 O2 (g) ® CO2 (g) + 2 H2O (l), how many moles of methane CH4 will react with 7.0 moles of molecular oxygen?
2. Ammonia reacts with molecular oxygen to form nitrogen monoxide and water vapor:
4 NH3 (g) + 5 O2 (g) ® 4 NO (g) + 6 H2O (l)
How many moles of H2O are formed when 2.0 moles of NH3 react according to the equation?
3. How many moles of phosphorous acid (H3PO3) are formed when 2.0 moles of water react according to the equation:
PCl3 (l) + 3 H2O (l) ® H3PO3 (aq) + 3 HCl (aq)
4. Using the equation in question #3, how many grams of HCl are formed when 3.00 mol H2O react?
5. How many grams of H2 can be formed by the reaction of 0.425 mol of Al with sufficient HCl?
2 Al (s) + 6 HCl (aq) ® 2 AlCl3 (aq) + 3 H2 (g)
6. The element vanadium is obtained from vanadium oxide. When vanadium oxide is mixed with calcium and heated to a high temperature the following reaction occurs.
V2O5 (s) + 5 Ca (l) ® 2 V (l) + 5 CaO (s)
How many grams of calcium oxide are produced for every 1.00 kg of vanadium produced?
7. How many grams of Mg(OH)2 (s) are required to completely neutralize 54.0 g of a HCl (aq). Complete and balance the equation first.
8. How many grams of chlorine can be produced by the complete reaction of 10.0 g of MnO2 according to the following equation?
MnO2 (s) + 4 HCl (aq) ® MnCl2 (aq) + Cl2 (aq) + 2 H2O (l)
9. How many grams of HCl are required to react with 10.0 g of MnO2 according to the following equation?
MnO2 (s) + 4 HCl (aq) ® MnCl2 (aq) + Cl2 (aq) + 2 H2O (l)
10. What mass of H2O is formed by the complete reaction of 2.50 g NH3 given that
4 NH3 (g) + 5 O2 (g) ® 4 NO (g) + 6 H2O (l)
11. Ammonia reacts with diatomic oxygen to form nitrogen monoxide and water vapor:
4 NH3 (g) + 5 O2 (g) ® 4 NO (g) + 6 H2O (l)
When 40.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reactant?
12. How many grams of water could be made from 3.0 mol H2 and 3.0 mol O2? Write and balance the equation.
13. 27.0 g of P and 68.0 g of I2 are reacted according to the following equation:
2 P (s) + 3 I2 (s) ® 2 PI3 (s)
How many grams of the excess reagent remain after the limiting reagent is consumed?
14. What is the theoretical yield in grams of vanadium that can be produced by the reaction of 40.0 g of V2O5 with 40.0 g of calcium according to the following equation?
V2O5 (s) + 5 Ca (l) ® 2 V (l) + 5 CaO (s)
15. What is the theoretical yield in grams of aluminum that can be produced by the reaction of 60.0 g of aluminum oxide with 30.0 g of carbon according to the following equation?
Al2O3 (s) + 3 C (s) ® 2 Al (s) + 3 CO (g)
16. What is the percentage yield of CO2 if 12.5 g pentane (C5H12) are burned in excess O2 and 15.1 g of carbon dioxide are formed?
C5H12 (l) + 8 O2 (g) ® 5 CO2 (g) + 6 H2O (l)
17. Calculate the molarity of a solution made from 25.2 g Na2SO4 and enough water to make 1600 mL of solution.
18. How many grams of KOH are required to prepare 250 mL of 2.0 M KOH solution?
19. Calculate the molarity of NiSO4 in a solution prepared by dissolving 10.0 g of nickel sulfate hexahydrate, NiSO4.6 H2O (M = 262.9 g/mol), in enough water to make 450 mL of solution.
20. How many grams of CaSO4 are required in order to make 428 mL of 0.15 M CaSO4?
21. What volume of 6.00 M HNO3 and what volume of water are required to prepare 500.0 mL of 1.00 M HNO3?
22. What volume of 3.00 M HCl and what volume of water are required to prepare 1.00 L of 1.00 M HCl?
23. In an acid-base titration, 42.90 mL of 0.825 M H2SO4 (aq) was required to neutralize 75.0 mL of NaOH (aq). First, write and balance the neutralization equation and then determine the molarity of the NaOH solution.
24. 22.5 mL of 0.383 M HCl (aq) is required to completely neutralize 20.0 mL of a Ba(OH)2 (aq) solution. Calculate the molarity of the Ba(OH)2 solution.
25. Calculate the volume of 1.82 M HCl (aq) required to neutralize 20.1 ml of 0.500 M Ba(OH)2 (aq) solution.
2 HCl (aq) + Ba(OH)2 (aq) ® BaCl2 (aq) + 2 H2O (l)
26. What volume of 0.152 M KMnO4 would react with 15.0 g of FeSO4?
5 Fe2+ (aq) + 8 H+ (aq) + MnO4- (aq) ® 5 Fe3+ (aq) + Mn2+ (aq) + 4 H2O (l)
27. KMnO4 solution can be standardized against As2O3. A 0.2116 g sample of As2O3 is first dissolved in acidic solution to form arsenious acid.
As2O3 (aq) + 3 H2O (l) ® 2 H3AsO3 (aq)
If 36.21 mL of KMnO4 solution is required to react with the above amount of As2O3, what is the molarity of the KMnO4 solution?
2 MnO4- (aq) + 6 H+ (aq) + 5 H3AsO3 ® 2 Mn2+ (aq) + 5 H3AsO4 (aq) + 3 H2O (l)
28. A sample of iron ore weighing 2.415 g is analyzed by converting the iron to Fe2+ and titrating with standard potassium dichromate:
6 Fe2+ (aq) + Cr2O72- (aq) + 14 H+ (aq) ® 6 Fe3+ (aq) + 2 Cr3+ (aq) + 7 H2O (l)
37.21 mL of 0.0213 M K2Cr2O7 was required to reach the equivalence point. Calculate the percentage of iron in the ore.