Exam #2 General Chemistry I - CHEM115 Fall 2006 (115e2f06)
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 1. Calcium sulfate precipitates from aqueous solutions as CaSO4•2H2O. When it is heated at 235°C for three
hours, all of the water of hydration is lost. If 172.17 g of the dihydrate is heated as described, the mass of the
solid produced will be
a. 118.13 g
b. 136.14 g
c. 154.16 g
d. 172.17 g
e. none of these
____ 2. In the conversion of bromate ion to bromide ion in acid solution,
a. bromine is oxidized
b. bromine is reduced
c. oxygen is oxidized
d. oxygen is reduced
e. More than one of these answers are correct.
____ 3. A compound that dissolves in water to yield only a small concentration of ions is called
a. a nonelectrolyte.
b. a weak electrolyte.
c. a strong electrolyte.
d. a saturated electrolyte.
e. none of these
____ 4. If a solution containing 4.000 g of NaOH is exactly neutralized by 80.00 mL of an aqueous HCl solution, the
molarity of the HCl solution must have been
a. 0.001250 m
b. 0.001370 m
c. 1.250 m
d. 1.370 m
e. none of these
____ 5. A crystalline compound of formula Mg(NO3)2•6H2O loses some of its water of hydration when it is heated,
but undergoes no other chemical changes. When a 10.0 g sample is heated in this way, the residue weighs
7.19 g. What is the formula of the residue?
a. Mg2(NO3)2•11H2O
b. Mg(NO3)2•4H2O
c. Mg(NO3)2•3H2O
d. Mg(NO3)2•2H2O
e. Mg(NO3)2•H2O
____ 6. An oxidizing agent is a substance that
a. is oxidized
b. causes oxidation
c. causes reduction
d. provides oxygen
e. none of these
