Chemistry 20 Review Questions:

1. What minimum volume of 0.50 mol/L aqueous magnesium chloride do you need to add to 60 mL of 0.30 mol/L aqueous silver nitrate in order to remove all the chloride ions?

2. Sulfuric acid, H2SO4(aq), can be neutralized by reacting it with aqueous barium hydroxide, Ba(OH)2(aq). The reaction is: H2SO4(aq) + Ba(OH)2(aq) → BaSO4(s) + 2H2O(l) What volume of 0.676 mol/L H2SO4(aq) can be neutralized by 22.7 mL of 0.385 mol/L Ba(OH)2(aq)?

3. When solutions of lead(II) nitrate and sodium iodide are mixed, a bright yellow precipitate appears.

a. Write the complete balanced equation for this double-replacement reaction.

b. What volume of 0.125 mol/L NaI(aq) is necessary to precipitate all the aqueous lead(II) ions in 25.0 mL of 0.100 mol/L Pb(NO3)2(aq)?

c. What mass of precipitate is formed in this reaction?

4. The cells lining your stomach secrete hydrochloric acid, with a typical concentration of 0.030 mol/L HCl(aq). Antacid tablets are used to relieve the pain of heartburn, caused by excess stomach acid irritating the lining of the esophagus just above your stomach. One Brand X antacid tablet contains 500 mg of CaCO3(s) and 110 mg of Mg(OH)2(s).

a. Calculate the volume of stomach acid neutralized by the CaCO3(s) in one Brand X antacid tablet according to the following equation: 2HCl(aq) + CaCO3(s) → CaCl2(aq) + CO2(g) + H2O(l)

b. Calculate the volume of stomach acid neutralized by the Mg(OH)2(s) in one Brand X tablet according to the following equation: 2HCl(aq) + Mg(OH)2(s) → MgCl2(aq) + 2H2O(l)

c. What total volume of stomach acid is neutralized by one Brand X antacid tablet?

5. For the reaction 2H2(g) + O2(g) → 2H2O(g)

a. What is the mole ratio of oxygen gas to water vapour?

b. What is the volume ratio of hydrogen gas to water vapour?

c. Calculate the volume of H2O(g) produced if 20 L of hydrogen gas reacts with the appropriate amount of oxygen.

6. Suppose that 12.0 L of nitrogen gas reacts with excess hydrogen gas to make ammonia gas, all at the same temperature and pressure. What volume of ammonia is expected from this reaction?

7. If 15 L of methane gas burns in a hot-water heater, what volume of oxygen gas at the same temperature and pressure is required for the methane to undergo complete combustion?

8. What would be the limiting reactant if 4.0 g of Cr(s) and 6.0 g of Fe(NO3)2(aq) were used in the reaction below?Cr(s) + Fe(NO3)2(aq) → Fe(s) + Cr(NO3)2(aq)

9. Predict the mass of zinc sulfide produced from the reaction of 15 g of zinc with 15 g of yellow sulfur (S8(s)).

10. Hydrogen fluoride, HF(g), is produced when concentrated sulfuric acid, H2SO4(aq), reacts with the mineral fluorspar, CaF2(s): CaF2(s) + H2SO4(aq) → 2HF(g) + CaSO4(s) Calculate the mass of HF(g) produced when 15 g of calcium fluoride is mixed with 20 g of H2SO4(aq).

11. If 15 g of zinc powder is stirred into an aqueous solution of copper(II) nitrate that contains 50 g of solute, does the zinc react completely?

12. Acrylonitrile, C3H3N(g), is the starting material for acrylic fibres. It is produced using the gas phase reaction of ammonia, NH3(g); oxygen from the air, O2(g); and propene, C3H6(g), according the following chemical equation: C3H6(g) + 2NH3(g) + 2O2(g) → C3H3N(g) + HCN(g) + 4H2O(g) What is the limiting reactant if 1.0 kg of C3H6(g) reacts with 600 g of NH3(g)?

13. For the following reaction: Fe(s) + CuCl2(aq) → FeCl2(aq) + Cu(s)

a. What is the predicted yield if 10.0 g of Fe(s) is reacted with an excess amount of CuCl2(aq)?

b. What would be the percentage yield if 9.0 g of Cu(s) is actually obtained?

14. Calculate the percentage yield for the following reaction if 60 g of SO2(s) is produced using 50 g of S8(s). S8(s) + 8O2(g) → 8SO2(s)

15. The set of data in the table below was collected during the titration analysis of an unknown hydrochloric acid sample with a sodium hydroxide titrant. Use the data to calculate the concentration of the acid. (Hint: Would you discard any data?)