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Problem 1
Which of the following mixtures has the highest pH? (a) Equal volumes of 1.0 M HCl and 1.0 M NaOH (b) Equal volumes of 0.1 M HNO3 and 0.1 M KOH (c) Equal volumes of 0.1 M HCN and 0.1 M NaOH (d) Equal volumes of 0.1 M NaF and 0.1 M HClProblem 3
A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in NaF. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 M HCl. (Ka = 3.5 x 10^-4) (a) 4.11 (b) 3.82 (c) 3.46 (d) 3.09Problem 4
What is the pH of a buffer solution prepared by dissolving 0.250 mol of NaH2PO4 and 0.075 mol of NaOH in enough water to make 1.00 L of solution? (Ka (H2PO4-) = 6.2 X 10^-8) (a) 6.32 (b) 6.83 (c) 7.21 (d) 7.71Problem 11
The pH titration curve applies to the titration of 40.0 mL of a 0.100 M solution of an acid with 0.100 M NaOH. What are the approximate pKa values for this acid?
(a) pKa1 = 5, pKa2 = 10 (b) pKa1 = 7, pKa2 = 11 (c) pKa1 = 5, pKa2 = 10, pKa3 = 13 (d) pKa1 = 5, pKa2 = 7, pKa3 = 10
Problem 12
What is the solubility-constant expression for Ca3(PO4)2 (s)? (a) [Ca2+]3 [PO43-]2 (b) [Ca2+]3 [PO43-]2 / [Ca3(PO4)2] (c) [Ca(PO4)2] / [Ca2+]3 [PO43-]2 (d) [Ca2+]2 [PO43-]3Problem 15
What is the molar solubility of BaF2 in a solution containing 0.0750 M LiF (Ksp = 1.7 x 10^-6) (a) 2.3 x 10^-5 M (b) 3.0 x 10^-4 M (c) 1.2 x 10^-2 M (d) 1.3 x 10^-3 MProblem 17
What is the molar solubility of AgI in 0.20 M NaCN? (a) 6.2 x 10^-4 M (b) 1.0 x 10^-1 M (c) 7.6 x 10^-2 M (d) 2.1 x 10^-3 MProblem 18
A solution containing sulfide ions is added to a solution of 0.036 M Cu2+ and 0.044 M Fe2+. At what concentration of sulfide ion will a precipitate begin to form? What is the identity of the precipitate? (a) 1.4 x 10^-16 M, FeS (b) 3.6 x 10^-35 M, CuS (c) 3.6 x 10^-35 M, FeS (d) 1.4 x 10^-16 M, CProblem 35
Consider the following table of standard reduction potentials:
(b) Which substances can be oxidized by B2+? Which can be reduced by D?
Problem 38
The strong acid HA is mixed with an equal molar amount of aqueous NaOH. Which of the following pictures represents the equilibrium state of the solution? (Na+ ions and solvent water molecules have been omitted for clarity.)
(A) (B) (C) (D)
Problem 39
The following pictures represent initial concentrations in solutions that contain a weak acid HA (pKa = 6.0) and its sodium salt NaA. (Na+ ions and solvent water molecules have been omitted for clarity.)
. (c) Draw a picture that represents the equilibrium state of solution (1) after the addition of two OH-ions.
Problem 39b
The following pictures represent initial concentrations in solutions that contain a weak acid HA (pKa = 6.0) and its sodium salt NaA. (Na+ ions and solvent water molecules have been omitted for clarity.)
. (b) Draw a picture that represents the equilibrium state of solution (1) after the addition of two H3O+ ions.
Problem 40a
The following pictures represent solutions that contain one or more of the compounds H2A, NaHA, and Na2A, where H2A is a weak diprotic acid. (Na+ ions and solvent water molecules have been omitted for clarity.)
(a) Which of the solutions are buffer solutions?
Problem 40b
The following pictures represent solutions that contain one or more of the compounds H2A, NaHA, and Na2A, where H2A is a weak diprotic acid. (Na+ ions and solvent water molecules have been omitted for clarity.)
(b) Which solution has the greatest buffer capacity?
Problem 41a
The following plot shows two pH titration curves, each representing the titration of 50.0 mL of 0.100 M acid with 0.100 M NaOH:
. (a) Which of the two curves represents the titration of a strong acid? Which represents a weak acid?
Problem 41b
The following plot shows two pH titration curves, each representing the titration of 50.0 mL of 0.100 M acid with 0.100 M NaOH:
. (b) What is the approximate pH at the equivalence point for each of the acids?
Problem 41c
The following plot shows two pH titration curves, each representing the titration of 50.0 mL of 0.100 M acid with 0.100 M NaOH:
. (c) What is the approximate pKa of the weak acid?
Problem 42a
The following pictures represent solutions at various stages in the titration of a weak base B with aqueous HCl. (Cl- ions and solvent water molecules have been omitted for clarity.)
. (a) To which of the following stages do solutions 1–4 correspond? (i) The initial solution before addition of any HCl (ii) Halfway to the equivalence point (iii) At the equivalence point (iv) Beyond the equivalence point
Problem 42b
The following pictures represent solutions at various stages in the titration of a weak base B with aqueous HCl. (Cl- ions and solvent water molecules have been omitted for clarity.)
. (b) Is the pH at the equivalence point more or less than 7?
Problem 43
The following pictures represent solutions at various stages in the titration of a weak diprotic acid H2A with aqueous NaOH. (Na+ ions and water molecules have been omitted for clarity.)
. (b) Which solution has the highest pH? Which has the lowest pH?
Problem 44a
The following pictures represent solutions at various stages in the titration of sulfuric acid H2A (A2- = SO4 2-) with aqueous NaOH. (Na+ ions and water molecules have been omitted for clarity.)
. (a) To which of the following stages do solutions 1–4 correspond? (i) Halfway to the first equivalence point (ii) Halfway between the first and second equivalence points (iii) At the second equivalence point (iv) Beyond the second equivalence point
Problem 44b
The following pictures represent solutions at various stages in the titration of sulfuric acid H2A (A2- = SO4 2-) with aqueous NaOH. (Na+ ions and water molecules have been omitted for clarity.)
. (b) Which solution has the highest pH? Draw a picture that represents the solution prior to addition of any NaOH.
Problem 46
The following pictures represent solutions of Ag2CrO4, which also may contain ions other than Ag+ and CrO42- that are not shown. Solution 1 is in equilibrium with solid Ag2CrO4. Will a precipitate of solid Ag2CrO4 form in solutions 2-4? Explain.
(1) (2) (3) (4)
Problem 47
Is the pH greater than, equal to, or less than 7 after the neutralization of each of the following pairs of acids and bases? (c) HBr and aniline (C6H5NH2)Problem 48a
Is the pH greater than, equal to, or less than 7 after the neutralization of each of the following pairs of acids and bases? (a) NaOH and benzoic acid (C6H5CO2H)
Problem 48c
Is the pH greater than, equal to, or less than 7 after the neutralization of each of the following pairs of acids and bases? (c) KOH and HI
Problem 49
Which of the following mixtures has the higher pH? (a) Equal volumes of 0.10 M HCN and 0.10 M NaOH (b) Equal volumes of 0.10 M HClO4 and 0.10 M NaOHProblem 51
Phenol (C6H5OH, Ka = 1.3 x 10^-10) is a weak acid used in mouthwashes, and pyridine (C5H5N, Kb = 1.8 x 10^-9) is a weak base used as a solvent. Calculate the value of Kn for the neutralization of phenol by pyridine. Does the neutralization reaction proceed very far toward completion?Problem 53
The equilibrium constant Kn for the neutralization of lactic acid (C3H6O3) and urea (CH4N2O) is 2.1 x 10^-4. What is Kb for urea? The Ka of lactic acid is 1.4 x 10^-4.Problem 55
Does the pH increase, decrease, or remain the same when the substances are added to the solutions? (a) LiF to an HF solution (b) KI to an HI solution (c) NH4Cl to an NH3 solution
