Chemistry EXAM 3

10) According to Brønsted-Lowry theory, acid-base reactions can be described as ________ reactions. A) electrolytic B) electron transfer C) gas phase D) nuclear transfer E) proton transfer

e

10) The dissolving process is exothermic when the energy A) released in solvation exceeds the energy used in breaking up solute-solute and solvent-solvent interactions. B) used in solvation exceeds the energy released in breaking up solute-solute and solvent-solvent interactions. C) released in solvation is about the same as the energy used in breaking up solute-solute and solvent-solvent interactions. D) used in solvation is less than the energy released in breaking up solute-solute and solvent-solvent interactions. E) used in solvation is about the same as the energy released in breaking up solute-solute and solvent-solvent interactions.

A

13) Consider the following four liquids: water: highly polar; H-bonding hexanol: slightly polar; some H-bonding chloroform: slightly polar; no H-bonding octane: non-polar; no H-bonding Which pair of liquids is immiscible?

A

14) The term miscible is used to describe which type of solution? A) liquid/liquid B) liquid/solid C) gas/liquid D) gas/gas E) all of the above

A

26) Calculate the concentration of nitrogen gas in water with a nitrogen gas at a partial pressure of 0.826 atm above it. Henry's law constant for nitrogen in water is 6.8 × 10-4 mol/L-atm. A) 5.6 × 10-4 M B) 8.2 × 10-3 M C) 1.2 × 103 M D) 0.43 M

A

6) In a mixture of 5 mL water, 10 mL alcohol, and 50 mL acetone the solvent(s) is(are) A) acetone. B) alcohol. C) water. D) acetone and alcohol. E) alcohol and water.

A

4) The number of components in a solution is A) at least 2. B) 3. C) 4. D) 5. E) 6.

A) at least 2.

89) Explain the difference between osmosis and dialysis.

Answer: Osmosis is when solvent molecules move across a semi-permeable membrane. Dialysis allows both solvent and small solute particles to cross a membrane.

12) A substance represented by a formula written as MxLOy ∙ zH2O is called a A) colloid. B) solid hydrate. C) solute. D) solvent. E) suspension.

B

15) Which of the following would be immiscible with carbon tetrachloride, CCl4? A) C6H12 B) CH3CH2OH C) Br2 D) C3H8 E) C4H10

B

16) Which of the following is miscible with CH3CH2OH? A) CH3CH2CH3 B) CH3OH C) CCl4 D) CH3CH3 E) CBr4

B

20) Which of the following has the least effect on the solubility of a solid in a liquid solvent? A) temperature B) pressure C) nature of the solvent D) nature of the solute E) concentration of solute

B

22) The solubility of gases in liquids A) increases as temperature increases and increases as pressure increases. B) decreases as temperature increases and increases as pressure increases. C) decreases as temperature increases and decreases as pressure increases. D) increases as temperature increases and decreases as pressure increases. E) is independent of temperature and increases as pressure increases.

B

7) Which statement best explains the meaning of the phrase "like dissolves like"? A) A solvent will easily dissolve a solute of similar mass. B) A solvent and solute with similar intermolecular forces will readily form a solution. C) The only true solutions are formed when water dissolves a non-polar solute. D) The only true solutions are formed when water dissolves a polar solute. E) None of these statements is correct.

B

8) When a solid dissolves, each molecule is removed from the crystal by interaction with the solvent. This process of surrounding each ion with solvent molecules is called A) dilution. B) solvation. C) electrolysis. D) hemolysis. E) crenation.

B

11) The exothermic step in the dissolution of NaCl in water is A) the separation of the ions in the salt. B) the separation of the water molecules. C) solvation (hydration) of the ions from the salt. D) separation of the ions in the salt and the separation of the water molecules.

C

19) Which statement about solubility is not true? A) No additional solute will dissolve in a saturated solution. B) A supersaturated solution is unstable. C) Solubility of ionic solids increases greatly with temperature. D) In a solution containing excess solute, an equilibrium exists between dissolved and undissolved solute. E) The solubility of substances is measured as g solute/100 mL solvent.

C

2) Which homogeneous mixture is opaque and has particles large enough to be filtered? A) colloid B) solution C) suspension D) both colloids and suspensions E) none of the above

C) suspension

18) A supersaturated solution A) contains as much solvent as it can hold. B) contains no double bonds. C) contains dissolved solute in equilibrium with undissolved solid. D) will rapidly precipitate if a seed crystal is added. E) none of the above

D

1) All of the following statements describing solutions are true except A) making a solution involves a physical change. B) solutions are homogeneous. C) the particles in a solution are atomic or molecular in size. D) solutions are colorless. E) solutions are transparent

D) solutions are colorless.

17) Which one of the following compounds would be least soluble in water? A) CH3NH2 B) CH3CH2OH C) CH3COOH D) CH3OCH3 E) CH3CH2CH2CH2CH3

E

21) Which of the following statements about the solubility of gases in liquids is not correct? A) A warm can of soda fizzes more than a cold can of soda when opened because gases are less soluble at higher temperature. B) An opened can of soda goes "flat" because the partial pressure of carbon dioxide is lower in the atmosphere than in the unopened can. C) A solution stored under an atmosphere of pure nitrogen will contain more dissolved nitrogen than the same solution stored under air because air is only 80% nitrogen. D) Fish kills may occur in the summertime because an inadequate amount of oxygen is dissolved in the water. E) none of the above

E

5) Which of the following can serve as the solvent in a solution? A) a gas B) a liquid C) a solid D) a mixture of commingled liquids E) all of the above

E

9) Water can be used to dissolve which type of compounds? A) nonpolar compounds B) polar compounds C) ionic compounds D) both A and B E) both B and C

E

23) In general, the solubility of ________ in water decreases as temperature increases. A) gases B) solids C) liquids D) none of these E) all of these

a

33) Which solution is the most concentrated? Each choice refers to the same solute and solvent. A) 2.4 g solute in 2 mL solution B) 2.4 g solute in 5 mL solution C) 20 g solute in 50 mL solution D) 30 g solute in 150 mL solution E) 50 g solute in 175 mL solution

a

39) What is the molarity of a solution prepared by dissolving 1.25 mol of AgNO3 in enough water to make 625 mL of solution? A) 2.00 M B) 0.00200 M C) 0.500 M D) 0.0118 M E) 0.340 M

a

42) How many moles of solute are present in 12.0 L of 3.00 M HCl? A) 36.0 mol B) 4.00 mol C) 0.250 mol D) 3.00 mol E) 0.750 mol

a

46) Calculate the concentration in ppm of a pollutant that has been measured at 450 mg per 150 kg of sample. A) 3.0 ppm B) 6.0 ppm C) 3000 ppm D) 330 ppm E) none of the above

a

60) What is the final concentration of a solution prepared by adding water to 50.0 mL of 1.5 M NaOH to make 1.00 L of solution? A) 0.075 M B) 0.030 M C) 1.5 M D) 7.5 M E) 30 M

a

62) What is the final concentration if 100 mL of water is added to 25.0 mL of 6.0 M NaCl? A) 1.2 M B) 1.5 M C) 6.0 M D) 24 M E) 30 M

a

63) How many mL of 16 M NH3 are needed to prepare 2.00 L of a 2.00 M solution? A) 250 mL B) 125 mL C) 16 mL D) 8.0 mL E) 4.0 mL

a

64) How many mL of 14.5 M NH3 are needed to prepare 2.00 L of a 1.00 M solution? A) 138 mL B) 69.0 mL C) 276 mL D) 29.0 mL E) 7.25 mL

a

68) Which one of the following would act like a strong electrolyte in an aqueous solution? A) KNO3 B) CH3OH C) CCl4 D) NH3

a

73) How many grams are in 10.0 mEq of Ca2+? A) 0.201 g B) 40.1 g C) 20.1 g D) 0.802 g E) 0.401 g

a

9) What is the conjugate base of HSO4-? A) SO42- B) H2SO4 C) H3O+ D) OH- E) H2SO3

a

2) The H3O+ ion is called the ________ ion. A) hydroxide B) hydronium C) hydrogen D) protium E) water

b

25) The solubility of nitrogen in water exposed to the atmosphere, where the partial pressure of nitrogen is 593 mm, is 5.3 × 10-4 M. At the same temperature, what would be the solubility of pure nitrogen, at a pressure of 760 mm?

b

27) All of the statements about molarity are correct except A) the abbreviation is M. B) the interpretation of the symbol is "moles of solute per mole of solvent." C) moles = molarity × volume. D) volume = moles/molarity. E) the molarity of a diluted solution is less than the molarity of the original solution.

b

36) What is the molarity of a solution prepared by dissolving 3.50 mol NaCl in enough water to make 1.50 L of solution? A) 0.429 M B) 2.33 M C) 5.25 M D) 87.8 M E) 137 M

b

37) What is the molarity of a solution prepared by dissolving 10.0 g of acetone, C3H6O, in enough water to make 125 mL of solution? A) 4.65 M B) 1.38 M C) 0.0465 M D) 0.0214 M E) 0.0125 M

b

58) Which procedure will produce 250 mL of a solution that is 4% by volume alcohol in water? A) 4 mL of alcohol is mixed with enough water to make 250 mL of solution. B) 10 mL of alcohol is mixed with enough water to make 250 mL of solution. C) 4 mL of alcohol is mixed with 250 mL of water. D) 10 mL of alcohol is mixed with 250 mL of water. E) none of the above

b

69) Considering 1.0 M solutions of each substance, which contains the largest concentration of ions? A) K2SO4 B) FeCl3 C) NaOH D) NH3 E) KCl

b

70) A water solution of sodium chloride is a good conductor of electricity. Due to this property, table salt is classified as a(n) A) weak electrolyte. B) strong electrolyte. C) non-electrolyte. D) semi-electrolyte. E) none of these.

b

76) Which statement comparing solutions with pure solvents is not correct? A) A solution containing a non-volatile solute has a lower vapor pressure than pure solvent. B) A solution containing a non-volatile solute has a lower boiling point than pure solvent. C) A solution containing a non-volatile solute has a lower freezing point than pure solvent. D) A solution will have a greater mass than an equal volume of pure solvent if the solute has a molar mass greater than the solvent. E) none of the above

b

81) Which aqueous solution will have the lowest freezing point? A) 0.60 molal sucrose B) 0.50 molal KF C) 0.60 molal glucose D) 0.24 molal FeI3

b

86) Which solution has the greatest osmolarity? A) 0.6 M NaCl B) 0.35 M AlCl3 C) 0.14 M KF D) 0.2 M CaBr2 E) 0.10 M KNO3

b

87) After swimming in the ocean for several hours, the swimmers noticed that their fingers appeared to be very wrinkled or shriveled up. This is an indication that seawater is ________ relative to the fluid in cells. A) isotonic B) hypertonic C) hypotonic D) none of these

b

24) Pressure has a large effect only on the solubility of ________ in liquids. A) liquid B) solid C) gas D) all of the above E) none of the above

c

28) How many grams of NaOH are needed to make 750 mL of a 2.5% (w/v) solution? A) 3.9 g B) 7.5 g C) 19 g D) 20 g E) 50 g

c

29) What is the % (w/v) concentration of a solution containing 25.0 g of solute in 400. mL of solution? A) 2.50% B) 5.00% C) 6.25% D) 12.5% E) 25.0%

c

31) How much NaOH is present in a 250. mL sample of a 5.00% (w/v) solution? A) 5.00 g B) 10.0 g C) 12.5 g D) 25.0 g E) 250 g

c

32) How much NaCl is needed to make 50.0 mL of a 16% (w/v) solution? A) 2.0 g B) 4.0 g C) 8.0 g D) 12 g E) 16 g

c

38) What is the molarity of a solution prepared by dissolving 0.750 mol CaCl2 in enough water to make 0.500 L of solution? A) 0.375 M B) 0.667 M C) 1.50 M D) 83.2 M E) 166.5 M

c

4) A Brønsted-Lowry acid is a substance which A) produces hydrogen ions in aqueous solution. B) produces hydroxide ions in aqueous solution. C) donates protons to other substances. D) accepts protons from other substances. E) accepts hydronium ions from other substances.

c

40) What is the molarity of a solution prepared by dissolving 48.0 g of NaOH in enough water to make 1.50 L of solution? A) 0.0313 M B) 0.556 M C) 0.800 M D) 1.28 M E) 32.0 M

c

48) Which list includes all the pieces of lab equipment needed to prepare a 0.500 M solution of NaCl from the pure salt and water? A) buret; volumetric flask B) buret; electronic balance C) electronic balance; volumetric flask D) electronic balance; graduated cylinder E) volumetric pipet and bulb; volumetric flask

c

53) All of the water in a 0.200 M solution of NaCl was evaporated and 0.150 mole of NaCl was obtained. What was the original volume of the sample? A) 30.0 mL B) 333 mL C) 750. mL D) 1000 mL (1.00 × 103 mL) E) 1330 mL

c

57) How many grams of water are needed to prepare 250. g of a solution that is 5.00% by mass NaCl? A) 5.00 g B) 12.5 g C) 238 g D) 245 g E) 1250 g

c

6) A necessary requirement for a Brønsted base is A) the presence of water as a reaction medium. B) the presence of hydroxide in its formula. C) a lone pair of electrons in its Lewis dot structure. D) the production of hydronium ion upon reaction with water. E) the presence of a metal ion in its formula

c

65) How many mL of water should be added to 50.0 mL of a 15.0 M H2SO4 solution to give a final concentration of 0.300 M? A) 950 mL B) 1000 mL C) 2450 mL D) 2500 mL E) 2550 mL

c

66) What is the final concentration of a solution prepared by using 75.0 mL of 18.0 M H2SO4 to prepare 500. mL of solution? A) 8.33 × 10-3 M B) 1.20 M C) 2.70 M D) 2.35 M E) 15.7 M

c

71) Considering 0.10 M solutions of each substance, which contains the smallest concentration of ions? A) (NH4)3PO4 B) Ca(NO3)2 C) FeSO4 D) K2CO3 E) Na2SO4

c

72) How many grams are contained in one equivalent of iron (III) ion, Fe+3? A) 168 g B) 55.9g C) 18.6g D) 0.0537 g E) 6.02 × 1023 g

c

80) Which solution will have the lowest boiling point? A) 0.050 M KNO3 B) 0.075 M CaCl2 C) 0.025 M NH4NO3 D) 0.020 M Na3PO4 E) 0.10 M C6H12O6

c

83) If "A" contains 2% NaCl and is separated by a semipermeable membrane from "B" which contains 10% NaCl, which event will occur? A) NaCl will flow from "A" to "B". B) NaCl will flow from "B" to "A". C) Water will flow from "A" to "B". D) Water will flow from "B" to "A". E) none of the above

c

88) Red blood cells are placed in a solution and neither hemolysis nor crenation occurs. Therefore the solution is A) hypertonic. B) hypotonic. C) isotonic. D) isotopic. E) concentrated.

c

30) What is the % (w/v) concentration of a solution containing 8.0 grams of alcohol in 50.0 mL of solution? A) 2.0% B) 4.0% C) 8.0% D) 16% E) 50%

d

34) Which solution is the least concentrated? Each choice refers to the same solute and solvent. A) 2.4 g solute in 2 mL solution B) 2.4 g solute in 5 mL solution C) 20 g solute in 50 mL solution D) 30 g solute in 150 mL solution E) 50 g solute in 175 mL solution

d

4) A Brønsted-Lowry acid is a substance which A) produces hydrogen ions in aqueous solution. B) produces hydroxide ions in aqueous solution. C) donates protons to other substances. D) accepts protons from other substances. E) accepts hydronium ions from other substances.

d

43) Normal saline is 0.920% (w/v) NaCl in water. How many grams of NaCl are needed to prepare 15.0 L of normal saline? A) 1.38 g B) 16.3 g C) 53.8 g D) 138 g E) 807 g

d

44) How many grams of C6H12O6 are needed to prepare 2.50 L of a 5.00% (w/v) solution? A) 1.25 g B) 0.200 g C) 12.5 g D) 125 g E) 200. g

d

52) How many grams of CaCl2 are needed to prepare 125 mL of a 1.50 M solution? A) 0.188 g B) 1.69 g C) 3.00 g D) 20.8 g E) 37.0 g

d

54) A 20.0 mL sample of CuSO4 was evaporated to dryness, leaving 0.967 g of residue. What was the molarity of the original solution? A) 48.4 M B) 0.0207 M C) 0.0484 M D) 0.303 M E) 0.433 M

d

74) How many milliequivalents of chloride ion are contained in a sample that is determined to contain of chloride ion? A) 48.9 mEq B) 41.0 mEq C) 25.7 mEq D) 20.5 mEq E) 10.3 mEq

d

75) If a normal blood sample contains 4.5 mEq/L of calcium ion, how many mg of calcium are contained in a blood sample? A) 9.0 mg B) 5.6 mg C) 2.8 mg D) 2.3 mg E) 1.4 mg

d

77) Which has the highest boiling point? A) 0.1 M Na2SO4 B) 0.1 M glucose, C6H12O6 C) 0.1 M MgCl2 D) 0.1 M Al(NO3)3 E) pure water

d

8) Which of the following is a diprotic acid? A) acetic acid B) hydrochloric acid C) phosphoric acid D) sulfuric acid E) nitric acid

d

82) Adding solute to a solution increases each of the following except A) molality. B) boiling point. C) osmotic pressure. D) freezing point.

d

84) The passage of a solvent across a semipermeable membrane because of concentration differences is called A) dialysis. B) hemolysis. C) hydration. D) osmosis. E) solvation.

d

85) What is the osmolarity of a 0.20 M solution of KCl? A) 0.10 Osmol B) 0.20 Osmol C) 0.30 Osmol D) 0.40 Osmol E) 0.80 Osmol

d

1) Which statement concerning Arrhenius acid-base theory is not correct? A) An Arrhenius acid produces hydrogen ions in water solution. B) An Arrhenius base produces hydroxide ions in water solution. C) A neutralization reaction produces water plus a salt. D) Acid-base reactions must take place in aqueous solution. E) none of the above

e

3) When acids and bases react the product other than water is a A) hydrogen ion. B) hydroxide ion. C) hydronium ion. D) metal. E) salt.

e

35) Which information is necessary to determine the molarity of a solution if the chemical formula of the solute is known? A) only the mass of solute dissolved B) only the volume of solvent used C) the molar mass of both the solute and the solvent used D) the mass of solute dissolved and the volume of solvent added E) the mass of solute dissolved and the final volume of the solution

e

41) How many moles of HCl are present in 75.0 mL of a 0.200 M solution? A) 15.0 mol B) 2.67 mol C) 0.375 mol D) 0.275 mol E) 0.0150 mol

e

45) How many mL of a 5.00% (w/v) glucose solution are needed to provide 20.0 g of glucose? A) 5.00 mL B) 20.0 mL C) 4.00 mL D) 200. mL E) 400. mL

e

47) How many mL of 0.105 M AgNO3 are needed for an experiment that requires 0.00510 mol of AgNO3? A) 0.536 mL B) 17.8 mL C) 18.70 mL D) 20.6 mL E) 48.6 mL

e

49) Which list includes all the pieces of lab equipment needed to prepare 0.100 M H3PO4 from a 5.00 M solution of H3PO4? A) buret; volumetric flask B) buret; electronic balance C) electronic balance; volumetric flask D) electronic balance; graduated cylinder E) volumetric pipet and bulb; volumetric flask

e

55) How many mL of a 0.200 M KOH solution contains 10.0 g of KOH? A) 11.2 mL B) 50.0 mL C) 178 mL D) 281 mL E) 891 mL

e

56) How many mL of a 0.200 M HNO3 solution contains 10.0 g of HNO3? A) 2.00 mL B) 31.7 mL C) 159 mL D) 315 mL E) 793 mL

e

59) A 50.0 mL sample of a 6.0 M solution of HCl is diluted to 200. mL. What is the new concentration? A) 24.0 M B) 6.0 M C) 2.10 M D) 2.00 M E) 1.50 M

e

61) A 50.0 mL sample of a 12.0 M solution of HCl is diluted to 250. mL. What is the new concentration? A) 60.0 M B) 12.0 M C) 10.4 M D) 3.00 M E) 2.40 M

e

67) Which substance is not an electrolyte? A) NaCl B) HCl C) NH4NO3 D) KOH E) CH4

e

78) Which has the lowest boiling point? A) 0.1 M Na2SO4 B) 0.1 M glucose, C6H12O6 C) 0.1 M MgCl2 D) 0.1 M Al(NO3)3 E) pure water

e

Match the following. A) an ionic compound which attracts water molecules from the atmosphere B) a solution in which no more solute will dissolve and in which excess solute is visible in the container C) a substance which dissociates completely in solution, providing a relatively large number of ions to conduct electricity D) refers to a solution having a lower osmolarity than 0.30 Osmol E) an ionic compound which holds water molecules within its crystalline structure F) refers to two solutions having the same osmolarity G) a substance which does not dissociate in solution and therefore does not conduct electricity H) a solution in which more solute is dissolved than predicted for that particular temperature I) refers to a solution having a greater osmolarity than 0.30 Osmol J) the swelling and bursting of a red blood cell when placed in a solution of lower osmolarity than the cell itself K) the shrinking of a red blood cell when placed in a solution of greater osmolarity than the cell itself L) a solution in which more solute can be dissolved M) a substance which partially dissociates in solution, providing a relatively small number of ions to conduct electricity

hydrate hygroscopic saturated unsaturated supersaturated weak electrolyte non electrolyte hypotonic strong electrolyte hemolysis hypertonic crenation isotonic Answers: 90) E 91) A 92) B 93) L 94) H 95) M 96) G 97) D 98) C 99) J 100) I 101) K 102) F