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Chapter 17 Additional Aspects of Aqueous Equilibria. Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten. Troy Wood University of Buffalo Buffalo, NY 2006, Prentice Hall.
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Chapter 17Additional Aspects of Aqueous Equilibria Chemistry, The Central Science, 10th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Troy Wood University of Buffalo Buffalo, NY 2006, Prentice Hall
What is [H+] of a 0.050 M HF solution dissolved in 0.20 M NaF? Ka(HF) = 6.8 104. 1.7 104 M 3.4 104 M 6.8 104 M 1.4 103 M 2.7 103 M
Correct Answer: 1.7 104 M 3.4 104 M 6.8 104 M 1.4 103 M 2.7 103 M The solution to problem is on the following slide.
Correct Answer: - 4 K [HF] (6.8 10 )(0.050) + = = a [H ] - (0.20) [F ] + - = 4 [H ] 1.7 10
Calculate the pH of a 0.50 M solution of sodium acetate in 0.050 M acetic acid (HOAc). pKa(HOAc) = 4.74. 3.74 4.24 4.74 5.24 5.74
Correct Answer: 3.74 4.24 4.74 5.24 5.74 [base] = + pH p K log a [acid] [0.50] = + pH 4.74 log [0.050]
Calculate the pH of a buffer solution containing 0.25 moles sodium acetate and 0.30 moles acetic acid (HOAc) to which 0.20 moles HCl are added. pKa(HOAc) = 4.74. 3.74 4.24 4.74 5.24 5.74
Correct Answer: 3.74 4.24 4.74 5.24 5.74 [base] = + pH 4.74 log [acid] - [0.25 0.20] = + pH 4.74 log + [0.30 0.20] [0.05] = + = pH 4.74 log 3.74 [0.50]
What is the pH of an aqueous solution to which 51.0 mL of 0.10 M NaOH have been added to 50.0 mL 0.10 M HCl? 2.00 2.70 3.00 3.30 4.00
Correct Answer: 2.00 2.70 3.00 3.30 4.00 The solution to problem is on the following slide.
Correct Answer: Moles H+ = (0.10 M)(0.0500 L) = 0.0050 Moles OH = (0.10 M)(0.0490 L) = 0.0049 - (0.0050 0.0049) + = = 3 [H ] 1.0 10 + (0.050 0.049) pH = log(1.0 103) = 3.00
What is the pH of an aqueous solution to which 26.0 mL of 0.10 M NaOH have been added to 50.0 mL 0.050 M HCl? 10.00 10.70 11.00 11.30 12.00
Correct Answer: 10.00 10.70 11.00 11.30 12.00 The solution to problem is on the following slide.
Correct Answer: Moles H+ = (0.050 M)(0.050 L) = 0.0025 Moles OH = (0.10 M)(0.0260 L) = 0.0026 - (0.0026 0.0025) - = = 3 [OH ] 2.0 10 + (0.026 0.025) pOH = log(2.0 103) = 2.70 pH = 14.00 2.70 = 11.30
What is the molar solubility of BaF2 if its Ksp = 1.0 106? 3.1 103 M 1.0 102 M 6.3 103 M 8.0 103M
Correct Answer: 3.1 103 M 1.0 102 M 6.3 103 M 8.0 103M The solution to problem is on the following slide.
Correct Answer: Ksp = [Ba2+][F]2 Let x = [Ba2+]; [F] = 2x. Ksp = (x)(2x)2 = 4x3 x = (Ksp /4)1/3 x = 6.3 103
What is the molar solubility of CaF2 in 0.010 M NaF? Ksp = 3.9 1011? 9.5 106 M 1.9 107 M 3.9 107M 3.9 109M
Correct Answer: 9.5 106 M 1.9 107 M 3.9 107M 3.9 109M The solution to problem is on the following slide.
Correct Answer: Ksp = [Ca2+][F]2 Let x = [Ca2+]; [F] = 0.010 + 2x. Ksp = (x)(0.010)2 x = Ksp /(0.010)2 x = 3.9 107
Which of the following substances will not be more soluble in acidic solution than basic solution? The sinkhole below is a dire result of such “solubility.” AgCl Ni(OH)2 CaCO3 BaF2
Correct Answer: AgCl Ni(OH)2 CaCO3 BaF2 Of these, only AgCl does not produce a basic anion that will react with H+.
Calculate [Ag+] when a NaCN solution is added to 0.10 M AgNO3 (and the equilibrium [CN] = 0.10 M. Kf (Ag(CN)2) = 1 1021? 1 1017 M 1 1018 M 1 1019 M 1 1020M 1 1021M
Correct Answer: 1 1017 M 1 1018 M 1 1019 M 1 1020M 1 1021M The solution to problem is on the following slide.
Correct Answer: Kf = [Ag(CN)2]/[Ag+][CN]2 Assume: Ag+ initially is converted to Ag(CN)2 [Ag+] = [Ag(CN)2]/Kf [CN]2 [Ag+] = (0.10)/[1 1021](0.1)2 [Ag+] = 1 1018
Upon addition of 6 M HCl to an aqueous solution, a precipitate forms. Which of the following cannot be in the precipitate? AgCl Hg2Cl2 PbCl2 CuCl2
Correct Answer: AgCl Hg2Cl2 PbCl2 CuCl2 Chlorides of Ag+, Hg22+, and Pb2+ are insoluble.