SCH3UI-01 Exam Review Fall 2012
1. Determine the number of hydrogen atoms found in 5.61 mol of magnesium hydroxide, Mg(OH)2.
2. Balance the following equation by inspection: Bi2O3 + H2
3.
Balance the following equation by inspection: Al4C3 + H2O
Bi + H2O
CH4 + Al(OH)3
4. Translate the following into a balanced chemical equation: 2 moles of solid silver carbonate
decomposes into 4 mol of solid silver, 2 mol of gaseous carbon dioxide, and 1 mol of oxygen in the
gaseous state.
5. Consider the following reaction: Barium chloride solution is mixed with potassium sulphate solution to
produce a solid precipitate barium sulphate and a solution of potassium chloride.
For this reaction, write
(a) a balanced chemical equation
(b) a total ionic equation
(c) a net ionic equation
6. Sodium thiosulfate, Na2S2O3, can be used as a fixer in the field of photography. Calculate the
percentage composition, by mass, of each element in sodium thiosulfate.
7. Consider the following balanced equation: LiAlH4 + 4H2O
LiOH + Al(OH)3 + 4H2
How many grams of Al(OH)3 will be produced from the hydration of 4.20 g of LiAlH4?
8. Students in a chemistry lab are making the compound cobalt(II) carbonate. It can be made by reacting
sodium carbonate solution with cobalt(II) chloride solution. Calculate the volume of 1.0 mol/L
cobalt(II) chloride solution required to completely react with 250 mL of 1.5 mol/L sodium carbonate.
9. A titration was performed on a 10.00-mL sample of water taken from an acidic lake. If it took 8.66 mL
of 0.0512 mol/L NaOH(aq) to neutralize the sulfuric acid in the lake water sample, calculate the
concentration of the sulfuric acid. What is the pH of this lake water?
10. A commercial rust remover contains 7.30 mol/L of phosphoric acid. Calculate the mass of calcium
carbonate scale inside a coffeemaker that can be dissolved by 45.0 mL of this solution.
2H3PO4(aq) + 3CaCO3(s)  Ca3(PO4)2(s) + 3CO2(g) + 3H2O(l)