MULTIPLE CHOICE QUESTIONS
1.) A 1.0 sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of CaCl2. What is the minimum number of moles of AgNO3 that must be added to the solution in order to precipitate all of the Cl¯ as AgCl(s) ? (Assume that AgCl is insoluble.)
(A) 0.10 mol (B) 0.20 mol (C) 0.30 mol (D) 0.40 mol (E) 0.60 mol 2.) A molecule or an ion is classified as a Lewis acid if it
(A) accepts a proton from water (B) accepts a pair of electrons to form a bond (C) donates a pair of electrons to form a bond (D) donates a proton to water
(E) has resonance Lewis electron-dot structures
3.) A yellow precipitate forms when 0.5 M NaI(aq) is added to a 0.5 M solution of which of the following ions?
A) Pb2+(aq) B) Zn2+(aq) C) CrO
42¯(aq) D) SO42¯(aq) E) OH¯(aq)
4.) A 40.0 mL sample of 0.25 M KOH is added to 60.0 mL of 0.15 M Ba(OH)2. What is the molar concentration of OH¯(aq) in the resulting solution? (Assume that the volumes are additive) A) 0.10 M B) 0.19 M C) 0.28 M D) 0.40 M E) 0.55 M
5.) The volume of distilled water that should be added to 10.0 mL of 6.00 M HCl(aq) in order to prepare a 0.500 M HCl(aq) solution is approximately
A) 50.0 mL B) 60.0 mL C) 100. mL D) 110. mL E) 120. mL 6.) 2 H2O + 4 MnO4¯ + 3 ClO2¯ ---> 4 MnO2 + 3 ClO4¯ + 4 OH¯
Which element is being reduced above?
(A) H (B) ClO4¯ (C) Cl (D) O (E) Mn
7.) HSO4¯ + H2O H3O+ + SO42¯
In the equilibrium represented above, the species that act as bases include which of the following?
I. HSO4¯ II. H2O III. SO42¯
(A) II only (B) III only (C) I and II (D) I and III (E) II and III
8.) Given that a solution is 5 percent sucrose by mass, what additional information is necessary to calculate the molarity of the solution?
I. The density of water II. The density of the solution III. The molar mass of sucrose
9.) Mass of an empty container = 3.0 grams
Mass of the container plus the solid sample = 25.0 grams Volume of the solid sample = 11.0 cubic centimeters
The data above were gathered in order to determine the density of an unknown solid. The density of the sample should be reported as
(A) 0.5 g/cm3 (B) 0.50 g/cm3 (C) 2.0 g/cm3 (D) 2.00 g/cm3 (E) 2.27 g/cm3
10.) Which of the following has the lowest conductivity?
(A) 0.1 M CuS04 (B) 0.1 M KOH (C) 0.1 M BaCl2 (D) 0.1 M HF (E) 0.1 M HNO3
11.) If 87 grams of K2 SO4 (molar mass 174 grams) is dissolved in enough water to make 250 milliliters of solution, what are the concentrations of the potassium and the sulfate ions?
[K+] [SO
42¯]
(A) 0.020 M 0.020 M
(B) 1.0 M 2.0 M
(C) 2.0 M 1.0 M
(D) 2.0 M 2.0 M
(E) 4.0 M 2.0 M
12.) What volume of 0.150-molar HCl is required to neutralize 25.0 millilters of 0.120-molar Ba(OH)2?
(A) 20.0 mL (B) 30 0 mL (C) 40.0 mL (D) 60.0 mL (E) 80.0 mL 13.) 6 I¯ + 2 MnO4¯ + 4 H2O(l) 3 I2(s) + 2 MnO2(s) + OH¯
Which of the following statements regarding the reaction represented by the equation above is correct?
(A) Iodide ion is oxidized by hydroxide ion. (B) MnO4¯ is oxidized by iodide ion.
(C) The oxidation number of manganese changes from +7 to +2. (D) The oxidation number of manganese remains the same. (E) The oxidation number of iodine changes from -1 to 0.
15.) A measured mass of an unreactive metal was dropped into a small graduated cylinder half filled with water. The following measurements were made.
Mass of metal = 19.611 grams
Volume of water before addition of metal = 12.4 milliliters Volume of water after addition of metal = 14.9 milliliters The density of the metal should be reported as
(A) 7.8444 grams per mL (B) 7.844 grams per mL (C) 7.84 grams per mL (D) 7.8 grams per mL (E) 8 grams per mL
16.) All of the following species can function as Brönsted-Lowry bases in solution EXCEPT (A) H2O (B) NH3 (C) S2¯ (D) NH4+ (E) HCO3¯
17.) How many moles of solid Ba(NO3)2 should be added to 300. milliliters of 0.20-molar Fe(NO3)3 to increase the concentration of the NO3¯ ion to 1.0-molar? (Assume that the volume of the solution remains constant.)
(A) 0.060 mole (B) 0.12 mole (C) 0.24 mole (D) 0.30 mole (E) 0.40 mole 18.) How many grams of NaOH (MW = 40.0) are there in 500.0 mL of a 0.175 M NaOH solution? a.) 2.19 × b.) 114 c.) 14.0 d.) 3.50 e.) 3.50 ×
19.) The net ionic equation for the reaction of a solution of aluminum sulfate and a solution of sodium hydroxide contains which of the following species?
(A) Al2+ (B) Na+ (C) SO
42-(D) Na2SO4 (E) Al(OH)3
20.) Which combination will produce a precipitate?
(A) and HCl (aq) (B) NaOH (aq) and HCl (aq)
(C) (aq) and (D) KOH (aq) and
(E) NaOH (aq) and HCl (aq)
FREE RESPONSE QUESTIONS
1971
Molarity and molality are two ways of expressing concentration.
(a) Clearly distinguish between them
(c) Indicate an experimental situation where expressing concentration as molality is particularly appropriate.
1987
In 1884 the Swedish chemist Svante Arrhenius proposed that salts dissociate into two or more separate, independent, ionic fragments when they dissolve in water.
(a) Give one piece of experimental evidence that more than 1 mole of particles is formed when 1 mole of a salt dissolves in water.
(b) Give one piece of experimental evidence that the particles formed when a salt dissolves in water are charged.
(c) Explain why the heat of neutralization is always the same when 1 mole of any monoprotic strong acid reacts with enough strong base to form a neutral solution.
(d) Explain why hydrogen chloride, HCl, dissociated when it dissolves in water but not when it dissolves in benzene.
1996
Concentrated sulfuric acid (18.4-molar H2SO4) has a density of 1.84 grams per milliliter. After dilution
with water to 5.20-molar, the solution has a density of 1.38 grams per milliliter and can be used as an electrolyte in lead storage batteries for automobiles.
(a) Calculate the volume of concentrated acid required to prepare 1.00 liter of 5.20-molar H2SO4.
(c) Calculate the volume of 5.20-molar H2SO4 that can be completely neutralized with 10.5 grams of
sodium bicarbonate, NaHCO3.
Answer the following questions, which refer to the 100 mL samples of aqueous solutions at 25°C in the stoppered flasks shown below.
a. Which solution has the lowest electrical conductivity? Explain.
4.) a.) A strip of magnesium metal is added to a solution of silver (I) nitrate: (i) write the balanced equation:
(ii) Which substance is oxidized in the reaction?
b.) A sample of solid iron (III) oxide is reduced completely with solid carbon. (i) Write the balanced equation:
