CHAPTER 4 STUDY GUIDE - 2

General Properties of Aqueous Solutions1. Which of the following schematic drawings best describes a solution of

Li2SO4?

2. Aqueous solutions of three different substances, AX, AY, and AZ, are represented by the three accompanying diagrams. Identify each substance as a strong electrolyte, a weak electrolyte, or a nonelectrolyte.

a. A = weak electrolyte, B = strong electrolyte, C = weak electrolyteb. A = weak electrolyte, B = nonelectrolyte, C = strong electrolytec. A = strong electrolyte, B = weak electrolyte, C = nonelectrolyted. A = strong electrolyte, B = nonelectrolyte, C = weak electrolyte

3. You are presented with a white solid. Because the container was labeled incorrectly, you aren’t sure whether it is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next, you add a Na2SO4 (aq) solution

and a white precipitate forms. What is the identity of the unknown solid?a. barium chlorideb. lead chloridec. zinc chlorided. None of these

Precipitation Reactions 4. Which combination will produce a precipitate?

a. NaF (aq) and HCl (aq) b. KOH (aq) and Mg(NO3)2 (aq)

c. AgNO3(aq) and Ca(C2H3O2)2 (aq)

d. NaC2H3O2 (aq) and HCl (aq)

e. NaOH (aq) and HCl (aq)

5. Aqueous potassium chloride will react with which one of the following in an exchange (metathesis) reaction?

a. sodium chloride b. sodium bromide c. barium nitrate d. lead nitratee. calcium nitrate

6. Aqueous solutions of a compound did not form precipitates with Cl-, Br-, I-, SO4

2-, CO32-, 4) PO4

3-, OH-, or S2-. This highly water-soluble compound produced the foul-smelling gas H2S when the solution was acidified. This compound is ________.

a. Li2CO3 b. Pb(NO3)2 c. (NH4)2S d. AgNO3 e. KBr

7.  A compound was found to be soluble in water. It was also found that addition of acid to an aqueous solution of this compound resulted in the formation of carbon dioxide. Which one of the following cations would form a precipitate when added to an aqueous solution of this compound?

a. Cr3+b. Rb+ c. NH4

+

d. K+ e. Na+

8. Separate samples of a solution of an unknown salt are treated with dilute solutions of HBr, H3SO4, and NaOH. A precipitate forms in all three cases. Which of the following cations could be present in the unknown salt solution?

a. K+

b. Pb2+

c. Ba2+

d. Cr4+

9. You know that an unlabeled bottle contains an aqueous solution of one of the following: AgNO3 , CaCl2 , Al2(SO4)3. A friend suggests that you test a portion of the solution with Ba(NO3)2 , record the results, and then test a new portion of the unknown solution with NaCl solutions. According to your friend’s logic, which of these chemical reactions could occur, thus helping you identify the solution in the bottle? Barium sulfate could precipitate

a. Silver chloride could precipitate b. Silver sulfate could precipitatec. More than one, but not all of the above reactions.d. All of the reactions in a-c

10. The labels have fallen off three bottles containing powdered samples of metals; one contains zinc, one lead, and the other platinum. You have three solutions at your disposal: 1 M sodium nitrate, 1 M nitric acid, and 1 M nickel nitrate. How could you use these solutions to determine the identities of each metal powder?

a. Test all solutions on all the powdered metals. Zinc will react with nitric acid and nickel nitrate, lead will react only with nitric acid, and platinum will not react with any solution

b. Test all solutions on all the powdered metals. Zinc will react with sodium nitrate and nickel nitrate, lead will react only with nitric acid, and platinum will not react with only sodium nitrate

c. Only two tests are needed. Test all metals with nitric acid and nickel nitrate. Zinc will react with both of these, lead will react with just nitric acid, and platinum won’t react with either of the solutions.

d. Only one test is needed. Test all metals with nickel nitrate, and the only one that reacts should be lead. The other two can be distinguished by their color – platinum is much more shiny

Acids and Bases and Neutralization Reactions

11. Which of the following solutions is the most acidic?a. 0.2 M LiOHb. 0.2 M HIc. 1.0 M methyl alcohol (CH3OH)d. 0.2 M CH3COOH

12. Which of the following solutions is the most basic?a. 0.6 M NH3

b. 0.150 M KOHc. 0.100 M Ba(OH)2

d. 1.0 M H2O

13. Which of the following statements is false?a. NH3 contains no OH- ions and yet its aqueous solutions are basicb. HF is a strong acid c. Although sulfuric acid is a strong electrolyte, an aqueous solution of

H2SO4 contains more HSO4- ions than SO4

2- ions. d. All of these are true

14. Which of the following is a weak base?a. Ca(OH)2

b. RbOHc. KOHd. Al(OH)3

15. Which of the following is a weak acid?a. H30+

b. HClc. HBrd. HClO4

16. The net ionic equation for formation of an aqueous solution of Al(NO3)3 via mixing solid Al(OH)3 and aqueous nitric acid is

a. Al(OH)3 (s) + 3NO3- (aq) → 3OH- (aq) + Al(NO3)3 (s)

b. Al(OH)3 (s) + 3NO3- (aq) → 3OH- (aq) + Al(NO3)3 (aq)

c. Al(OH)3 (s) + 3H+ (aq) → 3H2O (l) + Al3+ (aq)d. Al(OH)3 (s) + 3HNO3 (aq) → 3H2O (l) + Al(NO3)3 (aq)

e. Al(OH)3 (s) + 3HNO3 (aq) → 3H2O (l) + Al3+ (aq) + NO3-

(aq)

17. The net ionic equation for the reaction between aqueous sulfuric acid and aqueous sodium 12) hydroxide is

a. H+ (aq) + HSO4- (aq) + 2Na+ (aq) + 2OH- (aq) → 2H2O

(l) + 2Na+ (aq) + SO42-(aq)

b. 2H+ (aq) + SO42- (aq) + 2Na+ (aq) + 2OH- (aq) → 2H2O

(l) + 2Na+ (aq) + SO42- (aq)

c. H+(aq) + HSO4- (aq) + 2OH- (aq) → 2H2O (l) + SO4

2- (aq)

d. H+(aq) + OH-(aq) → H2O (l)

18. The reaction between strontium hydroxide and chloric acid produces

a. two weak electrolytes b. two molecular compounds c. a molecular compound and a weak electrolyte

d. two strong electrolytes e. a molecular compound and a strong electrolyte

Redox Reactions

19. Which region of the periodic table shown here contains elements that are easiest to oxidize?

a. Ab. Bc. Cd. D

20. In which reaction does the oxidation number of oxygen increase?

a. MgO (s) + H2O (l) → Mg(OH)2 (s) b. HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l)

c. 2SO2(g) + O2(g) → 2SO3(g)d. Ba(NO3)2 (aq) + K2SO4 (aq) → BaSO4 (s) + 2KNO3 (aq)e. 2H2O(l) → 2H2(g) + O2(g)

21. Based on the activity series, which one of the reactions below will occur?

a. 3FeBr2 (aq) + 2Au (s) → 3Fe (s) + 2AuBr3 (aq) b. SnCl2 (aq) + Cu (s) → Sn (s) + CuCl2 (aq) c. Zn (s) + MnI2(aq) → ZnI2(aq) + Mn (s) d. 2AgNO3 (aq) + Pb (s) → 2Ag (s) + Pb(NO3)2 (aq) e. 3Hg (l) + 2Cr(NO3)3 (aq) → 3Hg(NO3)2 + 2Cr (s)

22. The metal cadmium tends to form Cd2+ ions. The following observations were made in the laboratory: 1) When a strip of zinc metal is placed in CdCl2 (aq), cadmium metal is deposited on the strip, 2) When a strip of cadmium metal is placed in Ni(NO3)2 (aq), nickel metal is deposited on the strip. What are the correct net ionic equations for these two reactions?

A

B

CD

a. Zn2+ + Cd (s) Zn (s) + Cd2+ (aq)Cd(s) + Ni2+ (aq) Cd2+ (aq) + Ni (s)

b. Zn (s) + Cd2+ (aq) Cd (s) + Zn2+ (aq)Cd (s) + Ni2+ (aq) Cd2+ (aq) + Ni (s)

c. Zn (s) + Cd2+ (aq) Cd (s) + Zn2+ (aq)Cd2+ (aq) + Ni (s) Cd (s) + Ni2+ (aq)

d. Zn (s) + Cd2+ (aq) Cd (s) + Ni2+ (aq)Cd2+ (aq) + Ni (s) Cd (s) + Zn2+ (aq)

23. Based on #22, which elements most closely match the position of cadmium on the activity series?

a. chromium, iron, and cobaltb. zinc, nickel, and ironc. magnesium, aluminum, and sodiumd. gold, platinum, and mercury

24. Based on #22, which experiments could you perform to locate more precisely the position of cadmium on the activity series?

a. Place an iron strip in CdCl2 (aq). If Cd (s) is deposited, Cd is less active than Fe; if there is no reaction Cd is more active than Fe.

b. Place a cobalt strip in CdCl2 (aq). If Cd (s) is deposited, Cd is less active than Co; if there is no reaction Cd is more active than Co

c. Place a strip of Cr in CdCl2 (aq). If Cd (s) is deposited, Cd is less active than Cr; if there is no reaction Cd is more active than Cr

d. All of the abovee. A and B only

Concentrations 25. A 0.100 M solution of ________ will contain the highest

concentration of potassium ions. a. potassium hydrogen carbonate b. potassium iodide c. potassium phosphate d. potassium oxidee. potassium hypochlorite

26. Which solution has the same number of moles of KCl as 75.00 mL of 0.250 M solution of KCl?

a. 50.0 mL of 0.125 M solution of KCl b. 100 mL of 0.0500 Msolution of KCl c. 20.0 mL of 0.200 M solution of KCld. 129 mL of 0.145 M solution of KCl e. 25.0 mL of 0.175 M solution of KCl

27. Starting with solid sucrose C12H22O11, how would you prepare 250

mL of a 0.250 M solution of sucrose?a. 21.4 grams of sucrose and dissolve in 250 mL of distilled waterb. 342.2965 grams of sucrose and dissolve in 1.00 L of distilled water,

then take one half of that solution and add another 1.00 L of distilled water

c. 85.6 grams of sucrose and dissolve in 250 mL of distilled waterd. 85.6 grams of sucrose and dissolve in 500 mL of distilled water, then

take half of that solution and add 250 mL of distilled water.

28. A 0.200 M K2SO4 solution is produced by ________. 27) a. dissolving 43.6 g of K2SO4 in water and diluting to a total

volume of 250.0 mL b. dilution of 1.00 mL of 250 M K2SO3 to 1.00 L c. dissolving 20.2 g of K2SO4 in water and diluting to 250.0

mL, then diluting 25.0 mL of this solution to a total volume of 500.0 mL

d. dilution of 250.0 mL of 1.00 M K2SO4 to 1.00 L e. diluting 20.0 mL of 5.00 M K2SO4 solution to 500.0 mL

29. One cup of fresh orange juice contains 124 mg of ascorbic acid (vitamin C, C6H8O6). Given that one cup = 236.6 mL, what is the molarity of

vitamin C in orange juice?a. 2.98 x 10-3 Mb. 2.98 Mc. 0.524 Md. 6.98 x 10-2 M

30. The concentration of alcohol (CH3CH2OH) in blood, called blood

alcohol concentration, or BAC, is given in units of grams of alcohol per 100 mL of blood. The legal definition of intoxication, in many states of the US, is that the BAC is 0.08 or higher. What is the concentration of alcohol, in terms of molarity, in blood that has a BAC of 0.08?

a. 1.4 Mb. 0.012 Mc. 0.02 Md. 0.8 M

31. Vodka is an aqueous solution of approximately 6.86 M ethanol. If you wanted to make your own vodka, how many grams of ethanol, CH3CH2OH,

should you dissolve in water to make 1.00 L of vodka?a. 316 g b. 401 gc. 256 gd. 180 g

Solution Stoichiometry and Chemical Analysis

32. An aliquot (28.7 mL) of a KOH solution required 31.3 mL of 0.118 M HCl for neutralization. What mass (g) of KOH was in the original sample?

a. 0.173 b. 0.207 c. 0.414 d. 1.64 e. 7.28

33. You are titrating an acidic solution with a basic one, and just realized you forgot to add the indicator that tells you when the equivalence point is reached. In this titration, the indicator turns blue at the equivalence point from an initially colorless solution. You quickly grab a bottle of indicator solution and throw some into your titration beaker, and the whole solution turns dark blue! What should you do now that would be the most efficient use of time and materials?

a. Burn it. Burn it all!b. Add a known amount of base to the beaker to get it to

turn colorless again, then titrate the acid into the beaker to identify the equivalence point.

c. Add a known amount of the unknown acid to the beaker to turn it back to colorless, then carefully titrate the base into the solution to identify the equivalence point when it turns back to blue.

d. Start over.

34. What volume (L) of 0.250 M HNO3 is required to neutralize a solution prepared by dissolving 17.5 g of NaOH in 350 mL of water?

a. 0.44 b. 1.75 ×10-3 c. 50.0d. 1.75 e. 0.070

35. You are given two clear solutions of the same unknown monoprotic acid, but with different concentrations. Which statement is true?

a. There is no chemical method designed to tell the two solutions apart.

b. If the same volume of each sample was taken, then more base solution would be required to neutralize the one with lower concentration.

c. The product of concentration and volume of the less concentrated solution equals the product of concentration and volume of the more concentrated solution.

d. A smaller volume of the less concentrated solution contains the same number of moles of the acid compared to the more concentrated solution.

e. It would take more base solution (per milliliter of the unknown solution) to neutralize the more concentrated solution.

36. Which of the following would require the largest volume of 0.100 M sodium hydroxide solution for neutralization?

a. 20.0 mL of 0.0500 M nitric acidb. 15.0 mL of 0.0500 M hydrobromic acid c. 10.0 mL of 0.0500 M phosphoric acid d. 5.0 mL of 0.0100 M sulfuric acid e. 10.0 mL of 0.0500 M perchloric acid

37. A mysterious white powder is found at a crime scene. A simple chemical analysis concludes that the powder is a mixture of sugar and morphine (C17H19NO3), a weak base similar to ammonia. The crime lab takes 10.00 mg of the mysterious powder, dissolves it in 100.00 mL water, and titrates it to the equivalence point with 2.84 mL of a standard 0.0100 M HCl solution. What is the percentage of morphine in the white powder?

a. 8.10%b. 17.3%c. 49.7%d. 81.0%e. 32.6%

38. You want to analyze a silver nitrate solution. You could add HCl to the solution to precipitate out AgCl (s). What is the volume of a 0.15O M HCl (aq) solution is needed to precipitate the silver ions from 15.0 mL of a 0.200 M AgNO3 solution?

a. 20.0 mL b. 38.1 mLc. 15.8 mL d. 23.6 mL