PART I: MULTIPLE CHOICE QUESTIONS

1. Which of the following properties is CHEMICAL?

a) Water boils at 100°C.
b) Gases mix well with each other.
c) Sodium reacts with water to produce hydrogen.
d) Carbon is brittle.
e) Methane gas is colorless.
 

2. An atom of ⁵⁵Mn (manganese-55) contains:

a) 55 electrons
b) 55 protons
c) 55 protons and neutrons
d) 30 electrons
e) 25 neutrons
 

3. Which one of the following compounds is made of only NONMENTAL atoms?

a) NaCl
b) Sr(NO₃)
c) CaF₂
d) (NH₄)₂SO₄
e) KOH
 

4. Indicate which of the following formula/name pairs is CORRECT?

a) H₂S         hydrosulfurous acid
b) H₂SO₄    hydrosulfuric acid
c) H₂SO₃     sulfuric acid
d) SO₃^2-       sulfate anion
e) S^2-            sulfide anion
 
 

5. Which of the following ions is the permanganate ion?

a) MnO₂²⁺
b) Mn₂O₇^2-
c) MnO₄^-
d) MnO₃^-
e) Mn²⁺
 
 

6. Which of the following acids is the perchloric acid?

a) HCl
b) HClO
c) HClO₂
d) HClO₃
e) HClO₄
 

7. Cation of which metal would you justifiably expect to have a +1 charge?

a) Na
b) Ca
c) Al
d) Mg
e) Ba
 
 

8. How many K⁺ cations are required to form potassium phosphate with one phosphate anion?

a) 1
b) 2
c) 3
d) 4
e) 5
 
 

9. When the following reaction equation is balanced, KClO₃(s) ? KCl(s) + O₂(g)
the coefficients in front of KClO₃ and O₂ are, respectively:

a) 2, 1
b) 2, 2
c) 1, 3
d) 2, 3
e) 3, 2
 
 

10. Consult the solubility guidelines on page 111 in your textbook,
and decide which of the following compounds is insoluble in water:

a) KNO₃
b) NaCl
c) (NH₄)₃PO₄
d) Ag₂S
e) Ba(OH)₂
 
 

11. Which of the following reactions qualifies as a neutralization reaction?

a) Ca(OH)₂(aq) + 2 HCl(aq) ? CaCl₂(aq) + 2 H₂O(l)
b) Mg(NO₃)₂(aq) + 2 NaOH(aq) ? Mg(OH)₂(s) + 2 NaNO₃(aq)
c) AgNO₃(aq) + KCl(aq) ? AgCl(s) + KNO₃(aq)
d) Ca(OH)₂(aq) + 2 KCl(aq) ? CaCl₂(aq) + 2 KOH(aq)
e) H₂SO₄(aq) + Zn(s) ? ZnSO₄(aq) + H₂(g)
 

12. Which statement is FALSE?
 

a) 1 mol of oxygen gas, O₂, contains 2 moles of oxygen atoms.
b) 1 mol of oxygen gas, O₂, contains an Avogadro number of O2 molecules.
c) 1 mol of oxygen gas, O₂, weighs 32.00 g.
d) 1 mol of oxygen gas, O₂, contains 32.00 oxygen atoms.
e) 1 mol of oxygen gas, O₂, contains 1.20 x 10²⁴ oxygen atoms.
 

13. What is the oxidation number of sulfur in H₂SO₃?

a) -2
b) 0
c) +2
d) +4
e) +6
 
 

14. A hypothetical element has two naturally occurring isotopes with the following masses and fractional abundances:

Isotope Mass (amu)         Fractional Abundance

        94.91                                                  0.264

        95.93                                                  0.736

What is the average atomic mass (in amu) of this element?

a) 94.91
b) 95.12
c) 95.66
d) 95.82
e) 95.93
 

15. A compound contains 40.0% C, 6.7% H, and 53.3% O. What is the empirical formula of the compound?

a) CHO
b) CH₂O
c) CHO₂
d) C₂H₂O₂
e) C₂H₄O₂
 

16. A compound has an empirical formula of CH and molar mass of 78.11 g/mol. What is the molecular formula of the compound?

a) CH
b) CH₆
c) C₂H₂
d) C₄H₄
e) C₆H₆
 

17. Which of the following is the oxidation number of atom chromium in the chromate anion, CrO₄^2-?

a) 0
b) +3
c) +4
d) +6
e) +7
 
 

18. Which of the following reactions represents reduction?

a) Al(s) --> Al³⁺(aq) + 3e^-
b) H₂(g) --> 2H⁺(aq) + 2e^-
c) Cr₂O₇^2- + 14H⁺(aq) + 6e^- --> 2 Cr³⁺(aq) + 7H₂O(l)
d) 2Cl^-(aq) --> Cl₂(g) + 2e^-
e) Na(s) --> Na⁺(aq) + 1e^--
 

19. Which of the following statements is NOT true for the limiting reagent?

a) It gets completely consumed in the course of the reaction.
b) It determines the amount of product(s).
c) It is left over at the end of reaction.
d) Its amount limits the amount of products obtained in the reaction.
e) Once it has been consumed, the reaction stops.
 
 

20. If the theoretical yield of a reaction is 150 g of a product X, but the actual amount obtained is 89 g, the percent yield is .

a) 41%
b) 59%
c) 89%
d) 95%
e) 100%
 

21. What is the net ionic equation for the following neutralization reaction?
KOH(aq) + HCl(aq) Æ KCl(aq) + H2O(l)

a) KOH(aq)+ HCl(aq) Æ KCl(aq) + H₂O(l)

b) K⁺(aq) + Cl^-(aq) Æ KCl(aq)

c) H⁺(aq) + OH^-(aq) Æ H₂O(l)

d) HCl(aq) + H₂O(l) Æ H₃O⁺(aq) + Cl^-(aq)

e) no reaction
 
 

22. What is the volume of a 0.100M solution which contains 2.56 x 10^-3 moles of NaCl?

a) 0.256 mL
b) 25.6 mL
c) 39.1 mL
d) 150 mL
e) 391 mL
 

WRITTEN QUESTION: Show ALL work for full marks. Pay attention to significant figures, units and presentation.

23. Consider the following reaction: 2 NaOH(aq) + H₂S(g) ? Na₂S(aq) + 2H₂O(l). How many grams of sodium sulfide are formed if 5.0 g of hydrogen sulfide, H₂S(g) are bubbled into a solution containing 3.7 g of sodium hydroxide?