EXAM PRACTICE QUESTIONS Chapter 19 1 Calculate the H3O of a solution that is 0 100 M in HOCl and 0 0300 M in NaOCl Answer 1 17 cid 117 10 8 2 A solution is made by combining 500 mL of 0 10 M HF with 300 mL of 0 15 M NaF Calculate the pH of the solution Answer 3 10 3 What is the pH of a solution containing aqueous ammonia and ammonium nitrate in a molar Indicate which of the following combinations would produce a buffer ratio of 5 0 to 3 0 Answer 9 48 4 Answer A yes B no C yes D no 5 A HCN and KCN B HClO4 and NH4ClO4 C NH3 and NH4Br D KI and HI If 0 040 moles of solid NaOH is added to 1 0 L of a solution that is 0 1 M NH3 and 0 20 M NH4Cl what will be the pH of the resulting solution Assume no volume change due to the addition of the NaOH Answer 9 20 6 What is the pH of a solution that is 0 15 M in HOCl and 0 25 M NaOCl after 0 050 mole of HCl has been bubbled into the solution Assume no volume change Answer 7 46 7 Calculate the mass of solid NaCH3COO that must be added to 1 0 L of 0 20 M CH3COOH solution so that the pH of the resulting solution will be 5 00 Assume no volume change due to addition of solid NaCH3COO Answer 30 g 8 It is desired to buffer a solution at pH 4 30 What molar ratio of CH3COOH to NaCH3COO should be used Answer 2 8 9 Calculate the pH for a buffer solution prepared by mixing 100 mL of 0 60 M NH3 and 200 mL 0 45 mL of NH4Cl Answer 9 08 10 The nonionized form HIn of an acid indicator is yellow and its anion is blue The Ka of this indicator is 10 5 What will be the color of the indicator in a solution of pH 3 Answer yellow 11 What is the pH of the solution resulting from the addition of 30 0 mL of 0 200 M HClO4 to 20 0 mL of 0 150 M NaOH Answer 1 22 12 When a weak base is titrated with a strong acid the pH at the equivalence point is always 7 7 7 Answer 7 13 What is the pH at the equivalence point in the titration of 50 0 mL of 0 100 M hydrofluoric acid with 0 100 M sodium hydroxide Answer 7 92 14 At the equivalence point indicate whether the pH of the resulting solution is acidic basic or neutral for titrations of each of the following pairs of aqueous acids and bases A HClO4 with KOH B Ca OH 2 with HNO3 C CH3COOH with LiOH D HCN with NH3 E HI with NH3 A NaOH added to HF B HCl added to NH3 C HNO3 added to KOH D KOH added to HBr E NH3 is added to HNO2 Answer A neutral B neutral C basic D basic E acidic 15 Match the titrations described below A E to one of the titrations curves depicted below Answer I C II E III B IV A V D