3) Accounts for strands of DNA being held together into a double helix. 7) Accounts for the cohesive nature of water and its high surface tension

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1 AP Chemistry Test (Chapter 11) Multiple Choice (50%) Please use the following choices to answer questions 1-7. A) London dispersion forces B) Ion-ion attractions C) Dipole-dipole attractions D) Dipole-ion attractions E) Hydrogen bonding H) Dipole-induced dipole attractions I) Ion-induced dipole attractions 1) Accounts for the high boiling point of calcium nitrate 2) Accounts for the very slight solubility of salt in oil 3) Accounts for strands of DNA being held together into a double helix 4) Accounts for slight solubility of O 2 in water. 5) Accounts for wax (C n H 2n ) being a solid at room temperature 6) Accounts for salt dissolving in alcohol 7) Accounts for the cohesive nature of water and its high surface tension 8) The dissolution of water in octane (C 8 H 18 ) is prevented by which one? A) Temporary dipole attractions (London dispersion forces) between octane molecules B) Repulsion between like-charged water & octane molecules C) Dipole-dipole attractions between octane molecules D) Ion-dipole attractions between octane & water molecules E) Dipole-dipole attractions between water molecules 9) Which of the following unbalanced equations does not illustrate a dissolution process? A) KMnO 4 (s) + H 2 O (l) K + (aq) + MnO 4 (aq) B) Cl 2 (g) + H 2 O (l) HClO (aq) + H + (aq) + Cl (aq) C) HCl (g) + H 2 O (l) H + (aq) + Cl (aq) D) C 12 H 22 O 11 (s) + H 2 O (l) C 12 H 22 O 11 (aq) E) NaCl (s) + H 2 O (l) Na + (aq) + Cl (aq) 10) Which of the following is insoluble in C 6 H 6? A) CHCl 3 B) C 6 H 14 C) CH 3 CH 2 OH D) Br 2 E) C 3 H 8

2 11) Which of the following is least soluble in water? A) CH 3 OH B) CH 3 CH 2 OH C) CH 3 CH 2 CH 2 OH D) CH 3 CH 2 CH 2 CH 2 OH 12) Which one will increase the solubility of a gaseous solute in a liquid solvent? A) Decrease the pressure & decrease the temperature B) Decrease the pressure & increase the temperature C) Increase the pressure & decrease the temperature D) Increase the pressure & increase the temperature 13) A m solution of which one of the following solutes will have the lowest vapor pressure? A) KClO 4 B) Fe 2 (SO 4 ) 3 C) Cr(NO 3 ) 2 D) Na 2 SO 4 E) C 12 H 22 O 11 14) Which aqueous solution will have the highest boiling point? A) 0.40 M FeCl 2 B) 1.00 M NH 3 C) 0.50 M C 6 H 12 O 6 D) 0.20 M KI E) 0.30 M Mg(NO 3 ) 2 15) The normal boiling point (at 1 atm) of pure alcohol is 78 o C and the normal freezing point is 115 o C. Which one could represent the respective boiling and freezing points when the alcohol contains a solute? A) 78 o C and 115 o C B) 70 o C and 110 o C C) 82 o C and 124 o C D) 82 o C and 110 o C E) 78 o C and 124 o C 16) A clear liquid has no Tyndall effect at 25 o C. Which one could be true for the clear liquid? A) Heterogeneous mixture B) Heterogeneous mixture or compound C) Solution or colloid D) Element or compound E) Solution or compound 17) Please choose all true statements. A) All compounds are homogeneous. B) All solutions are pure. C) All colloids are heterogeneous. D) All pure substances are homogeneous. E) All solutions are homogeneous. 18) Which aqueous solution will have the lowest freezing point? A) 0.40 M NH 3 B) 0.20 M FeBr 3 C) 0.80 M C 6 H 12 O 6 D) 0.60 M NH 4 NO 3 E) 0.10 M Zn(ClO 3 ) 3

3 19) Which one is arranged in order of increasing solubility in water (least soluble to most soluble)? A) KNO 3 < CHCl 3 < CBr 4 B) CBr 4 < CH 3 OH < KNO 3 C) CBr 4 < KNO 3 < CHCl 3 D) CH 3 OH < CBr 4 < KNO 3 E) CH 3 OH < CBr 4 < CHCl 3 20) A saturated solution. A) contains as much solvent as it can hold. B) contains no double bonds. C) contains dissolved solute in equilibrium with undissolved solute. D) will rapidly precipitate solute if a seed crystal is added. E) cannot be attained. 21) Which one best describes the behavior of a seed crystal dropped into an unsaturated solution? A) It falls to the bottom of the solution undissolved. B) It dissolves readily in the solution C) It rapidly precipitates solute from the solution. D) It falls to the bottom of the solution & slowly dissolves. 22) What is the concentration of NO 3 in a solution that is M Al(NO 3 ) 3? A) M B) M C) 1.80 M D) 3.60 M E) 2.70 M Please use the attached solubility graph to answer questions ) What mass of NaNO 3 will dissolve in 200 g H 2 O at 10 o C to form a saturated solution? A) 160 g B) 80 g C) 90 g D) 40 g 24) When a saturated solution of KNO 3 in 100 g H 2 O is cooled from 50 o C to 35 o C, what mass of KNO 3 will crystallize or precipitate from the solution? A) 58 g B) 85 g C) 143 g D) 27 g 25) Which one is accurately described? A) A supersaturated solution forms when 80 g KNO 3 dissolves in 100 g H 2 O at 45 o C. B) An unsaturated solution forms when 75 g KNO 3 dissolves in 100 g H 2 O at 45 o C. C) A saturated solution forms when 115 g KNO 3 dissolves in 100 g H 2 O at 60 o C. D) A supersaturated solution forms when 100 g KNO 3 dissolves in 100 g H 2 O at 60 o C.

4 Problems (50%) 1) ml of M Al(ClO 3 ) 3 is mixed with ml of M Mg(ClO 3 ) 2. What is the resulting chlorate ion concentration? 2) A solution is 7.25% H 3 PO 4 by mass. What is the molality of the solution? 3) What mass of antifreeze (ethylene glycol) C 2 H 6 O 2 ) must be added to 9.00 L of water in your car s radiator to produce a solution that will not freeze until o C. Assume the density of water is exactly 1.00 g/ml. 4) What is the boiling point of a solution that contains 14.5 g Fe(NO 3 ) 2 dissolved in 30.0 g water? 5) A chemist is trying to identify a human hormone by its molar mass. A sample weighing g was dissolved in 20.0 g benzene. The normal freezing point of benzene is 5.50 o C, but the solution containing the hormone had a freezing point of o C. K f = 5.12 o C kg/mol for benzene. What is the molar mass of the hormone?

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