Problem Set 8 Chapter 17 1 Which of the following is not a strong acid 2 Which of the following is not amphiprotic HNO3 HF H2O HSO4 c d c d HC O4 HC e H2SO4 NH4 H2PO4 all choices e are amphiprotic 3 Which of the following is not a Bronsted Lowry acid H2O HCO3 c a b d e all choices are Bronsted Lowry acids Fe H2O 6 NH4 3 The ion HPO4 conjugate base of this ion is 1 while the conjugate acid is 2 2 has both a conjugate base as well as a conjugate acid The 5 The approximate pH of a 3 0 x 10 3 M solution of the strong acid H2SO4 is 1 H2PO4 1 PO4 1 PO4 1 HPO5 1 H2PO4 3 3 2 2 2 2 2 H3PO4 H2PO4 H2PO4 HPO3 3 PO4 3 5 3 0 2 5 2 2 3 0 a b a b a b c d e a b c d e 4 6 Which statement below is correct true Since HNO2 is a stronger acid than HF it must have a greater pKa Since HOC is a stronger acid than HCN then OC is a stronger base than CN The dissociation or ionization of HOC in water is HOC H2O HC 2OH The pH of a 0 10 M solution of acetic acid Ka 1 8 x 10 5 will be higher than the pH of a 0 10 M solution of formic acid Ka 1 8 x 10 4 If the Kb for CH3NH2 is 5 0 x 10 4 the Ka for CH3NH3 is 2 0 x 10 5 7 Which salt below will dissolve in water to yield an acidic solution 8 The Ka for HOBr is 2 4 x 10 9 Thus you can report the pKb for OBr as a b c d e a b c d e a b c d e NaNO2 K C O4 NH4NO3 Na2CO3 Mg Br2 4 2 x 10 6 9 62 5 38 8 62 1 38 9 If HClO2 is a stronger acid than HF which is stronger than HOCl then the order of strengths of the conjugate bases of these acids is a ClO F ClO2 b ClO2 ClO F e F ClO2 ClO c ClO ClO2 F d ClO2 F ClO 10 Look at problem 36 on page 798 of the text For the three equations presented pick the correct choice below a All have equilibria that lie predominantly to the right b All have equilibria that lie predominantly to the left c Two of the three have equilibria that lie predominantly to the left These are a and b in the problem d Two of the three have equilibria that lie predominantly to the left These are b and c in the problem e Two of the three have equilibria that lie predominantly to the left These are a and c in the problem ANSWERS TO SET 8 1 B 2 C 3 E 4 C 5 D 6 D 7 C 8 C 9 D 10 D 2 At 25oC the pH of a 1 75 M NaCN solution the Ka for HCN 4 0 x 10 10 is Problem Set 9 Chapter 17 1 The Ka for acetic acid is 1 8 x 10 5 What is the pH of a 3 18 M solution of this acid a b c d e a b c d e 2 12 4 74 1 50 4 24 2 62 11 82 9 64 4 58 2 18 9 42 a 3 54 b 1 77 c 3 23 d 3 14 e 3 30 3 A 0 0170 M solution of an acid has a pH 2 5 What is the pKa of this acid 4 Which 0 10M solution below has the lowest pH a NaCl b KCN c LiF d RbClO e all have the same pH 5 What is the equilibrium constant for the reaction of ammonium ion with formate ion a 1 0 X 10 13 b 5 6 X 10 11 c 3 1 X 10 6 d 1 8 X 10 5 e 3 2 X 105 6 What is the pH of a solution which results from mixing 150 mL of 0 50M acetic acid and 150 mL of 0 50M sodium hydroxide at 25oC a 2 67 b 9 07 c 4 93 d 8 26 e 7 00 7 Which theory and definition of an acid matches a Arrhenius acids are catalysts in reactions b Bronsted Lowry acids are proton scavengers c Lewis acids donate electrons pairs d All the above a c are correct definitions e All the above a c are incorrect definitions 8 Which solution has the greatest percent ionization a 1 0M HF b 0 10M HNO2 c 0 25M HOCl d 0 010 M copper II e 0 20M ammonium ion 9 Which of the following equations correspond to the Ka2 for phosphoric acid note the double equal sign means equilibrium a HPO4 2 aq H2O l H3O aq PO4 3 aq b PO4 3 aq H2O l HPO4 2 aq OH aq c H3PO4 aq H2O l H3O aq H2PO4 aq d H3PO4 aq 2 H2O l 2 H3O aq HPO4 2 aq e H2PO4 aq H2O l H3O aq HPO4 2 aq 10 What is the pH of 1 0M Na2SO3 aq solution at 25C 3 40 a b 6 03 c 10 60 d 7 96 e 10 40 ANSWERS TO SET 9 1 A 2 A 3 D 4 A 5 C 6 B 7 E 8 B 9 E 10 C