Multiple Choice (Choose the best answer.)

_____ 1. A glass of iced tea containing excess sugar at the bottom is said to be:

a) saturated
b) unsaturated
c) heterogeneous
d) both a) and c)
e) both b) and c)

_____ 2. A concentrated solution is one in which there is a:

a) small amount of solvent
b) small amount of solute
c) large amount of solute in a small amount of solvent
d) large amount of solute in a large amount of solvent
e) none of the above

_____ 3. Which of the following is a FALSE statement about electric charge?

a) There are only two kinds of electric charge.
b) Unlike charges attract.
c) Like charges repel.
d) Ions are created by the addition or subtraction of an electron to a neutral element.
e) Why two positive charges repel each other is well explained by modern theory.

_____ 4. Which of the following would likely conduct electricity?

I. CO₂ (aq) II. C₁₂H₂₂O₁₁ (aq) III. KI (s) IV. KI (aq)

a) IV only b) I, II, & IV only c) III & IV only d) I & II only e) none are correct

Questions 5 - 7 are about solutions of CdCl₂. The molar mass of cadmium chloride is 183 g.

_____ 5. If 300 mL of a solution contains 18.3 g CdCl₂, the molarity of the solution is:

a) 0.2 M b) 0.040 M c) 0.10 M d) 0.033 M e) none of these values

_____ 6. The solubility is sufficient so that a 9 M solution of CdCl₂ can be made. What mass of CdCl₂ would be present in 10.0 mL of 9 M solution?

a) 0.90 g b) 3.47 g c) 16.5 g d) 21.3 g e) 1.65 g

_____ 7. Consider these statements about boiling a CdCl₂ solution. Select the FALSE statement.

a) The freezing temperatureof the solution is higher than the freezing temperature of pure water.
b) The boiling temperature of the solution will be higher than that of pure water (at the same pressure).
c) The boiling temperature of the solution will rise as the solvent boils away.
d) As boiling continues, the concentration of CdCl₂ in solution will increase.
e) The solution boils when its vapor pressure is equal to the atmospheric pressure.

_____ 8. Which of the following statements is FALSE concerning a cadmium ion, Cd²⁺?

a) It contains two more protons than electrons.
b) It is formed by removing electrons from a neutral atom.
c) It would be attracted to a nitrate ion.
d) It is formed by adding two protons to a neutral atom.
e) If it gained two electrons, it would be electrically neutral.

_____ 9. The most concentrated solution from among those listed is:

a) 100 mL 0.25 M KCl
b) 150 mL 0.18 M NaOH
c) 75 mL 0.27 M KNO₃
d) 200 mL 0.25 M NaNO₃
e) It is impossible to tell.

_____ 10. Which of the following represents the formation of a chloride ion from a chlorine atom?

a) Cl + e^- Cl^-
b) Cl Cl + e^-
c) Cl Cl^- + p+
d) Cl^- Cl^- + e^-
e) Cl₂ 2 Cl^- + 2e^-

Short Answer/Calculation (Show or explain all work. Indicate proper units throughout problem.)

1. An aqueous solution of sodium sulfate was mixed with an aqueous solution of barium nitrate.

a) Write the ionic reaction. (If no reaction occurs, write the dissolution reactions for sodium sulfate and barium nitrate.)

 

b) If a reaction occurs, write the net ionic reaction.

 

2. What mass of KNO₃, potassium nitrate, is needed to make 3.00 x 10² mL of a 2.00 M solution? Describe how to make the solution.

 

 

3. Which of the following ionic compounds will dissolve in water? For soluble compounds, write dissolution (dissolving) reactions.

a) (NH₄)₂SO₄
b) Pb(NO₃)₂
c) BaS
d) Al(OH)₃

4. In Experiment 16A, 40.0 mL of 0.50 M HCl (aq) reacted with an excess of CaCO₃ (s) to form CO₂ (g), H₂O (l) and CaCl₂ (aq). How many grams of CaCO₃ (At. Wt. = 100 g/mol) reacted? Don't forget to write a balanced reaction.

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