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- Consider a buffer solution that contains equal concentrations of H2PO4- and HPO42-. Will the pH increase, decrease, or remain the same when each of the following substances is added? (a) Na2HPO4 (b) HBr (c) KOH (d) KI (e) H3PO4 (f) Na3PO4
Problem 79
- Consider the titration of 60.0 mL of 0.150 M HNO3 with 0.450 M NaOH. (a) How many millimoles of HNO3 are present at the start of the titration? (b) How many milliliters of NaOH are required to reach the equivalence point? (c) What is the pH at the equivalence point? (d) Sketch the general shape of the pH titration curve.
Problem 81
- Make a rough plot of pH versus milliliters of acid added for the titration of 50.0 mL of 1.0 M NaOH with 1.0 M HCl. Indicate the pH at the following points, and tell how many milliliters of acid are required to reach the equivalence point. (a) At the start of the titration (b) At the equivalence point (c) After the addition of a large excess of acid
Problem 82
- Consider the titration of 40.0 mL of 0.250 M HF with 0.200 M NaOH. How many milliliters of base are required to reach the equivalence point? Calculate the pH at each of the following points. (d) After the addition of 80.0 mL of base
Problem 85
- Consider the titration of 25.0 mL of 0.200 M HCO2H with 0.250 M NaOH. How many milliliters of base are required to reach the equivalence point? Calculate the pH at each of the following points: (c) At the equivalence point, (d) After the addition of 25.0 mL of base.
Problem 86
- On the same graph, sketch pH titration curves for the titra-tion of (1) a strong acid with a strong base and (2) a weak acid with a strong base. How do the two curves differ with respect to the following? (a) The initial pH
Problem 87
- Consider the titration of 50.0 mL of 0.010 M HA (Ka = 1.0 x 10^-4) with 0.010 M NaOH. (a) Sketch the pH titration curve, and label the equivalence point. (b) How many milliliters of 0.010 M NaOH are required to reach the equivalence point? (c) Is the pH at the equivalence point greater than, equal to, or less than 7? (d) What is the pH exactly halfway to the equivalence point?
Problem 88
- The equivalence point was reached in titrations of three unknown acids at pH 9.16 (acid A), 8.88 (acid B), and 8.19 (acid C). (a) Which is the strongest acid? (b) Which is the weakest acid?
Problem 91
Problem 93a
What is the pH at the equivalence point for the titration of 0.10 M solutions of the following acids and bases, and which of the indicators in Figure 17.5 would be suitable for each titration? (a) HNO2 and NaOH
Problem 93c
What is the pH at the equivalence point for the titration of 0.10 M solutions of the following acids and bases, and which of the indicators in Figure 17.5 would be suitable for each titration? (c) CH3NH2 (methylamine) and HCl
- What is the pH at the equivalence point for the titration of 0.20 M solutions of the following acids and bases? Which of the indicators in Figure 17.5 would be suitable for each titration? (c) Ba(OH)2 and HBr
Problem 94
Problem 95a
Consider the titration of 50.0 mL of a 0.100 M solution of the protonated form of the amino acid alanine (H2A+: Ka1 = 4.6 × 10–3, Ka2 = 2.0 × 10–10) with 0.100 M NaOH. Calculate the pH after the addition of each of the following volumes of base. (a) 10.0 mL
Problem 95b,c
Consider the titration of 50.0 mL of a 0.100 M solution of the protonated form of the amino acid alanine (H2A+: Ka1 = 4.6 × 10–3, Ka2 = 2.0 × 10–10) with 0.100 M NaOH. Calculate the pH after the addition of each of the following volumes of base. (b) 25.0 mL (c) 50.0 mL
Problem 95d
Consider the titration of 50.0 mL of a 0.100 M solution of the protonated form of the amino acid alanine (H2A+: Ka1 = 4.6 × 10–3, Ka2 = 2.0 × 10–10) with 0.100 M NaOH. Calculate the pH after the addition of each of the following volumes of base. (d) 75.0 mL
Problem 95e
Consider the titration of 50.0 mL of a 0.100 M solution of the protonated form of the amino acid alanine (H2A+: Ka1 = 4.6 × 10–3, Ka2 = 2.0 × 10–10) with 0.100 M NaOH. Calculate the pH after the addition of each of the following volumes of base. (e) 100.0 mL
- Consider the titration of 25.0 mL of 0.0200 M H2CO3 with 0.0250 M KOH. Calculate the pH after the addition of each of the following volumes of base: (a) 10.0 mL, (b) 20.0 mL, (c) 30.0 mL, (d) 40.0 mL.
Problem 96
Problem 97a,c
Consider the titration of 50.0 mL of 1.00 M H3PO4 with 1.00 M KOH. Calculate the pH after the addition of each of the following volumes of base. (a) 25.0 mL (c) 75.0 mL
Problem 97b,d
Consider the titration of 50.0 mL of 1.00 M H3PO4 with 1.00 M KOH. Calculate the pH after the addition of each of the following volumes of base. (b) 50.0 mL (d) 100.0 mL
- The titration of 0.02500 L of a diprotic acid solution with 0.1000 M NaOH requires 34.72 mL of titrant to reach the second equivalence point. The pH is 3.95 at the first equiva-lence point and 9.27 at the second equivalence point. If the acid solution contained 0.2015 g of the acid, what is the molar mass, pKa1, and pKa2 of the acid?
Problem 98
- For each of the following compounds, write a balanced net ionic equation for the dissolution of the compound in water, and write the equilibrium-constant expression for Ksp. (d) Hg2Cl2
Problem 99
- A particular saturated solution of PbI2 has [Pb2+] = 5.0 x 10^-3 M and [I-] = 1.3 x 10^-3 M. (a) What is the value of Ksp for PbI2? (b) What is [I-] in a saturated solution of PbI2 that has [Pb2+] = 2.5 x 10^-4 M? (c) What is [Pb2+] in a saturated solution that has [I-] = 2.5 x 10^-4 M?
Problem 101
- A particular saturated solution of Ca3(PO4)2 has [Ca2+] = [PO43-] = 2.9 x 10^-7 M. (c) What is [PO43-] in a saturated solution that has [Ca2+] = 0.010 M?
Problem 102
- If a saturated solution prepared by dissolving Ag2CO3 in water has [Ag+] = 2.56 x 10^-4 M, what is the value of Ksp for Ag2CO3?
Problem 103
- If a saturated aqueous solution of the shock-sensitive compound lead(II) azide, Pb(N3)2, has [Pb2+] = 8.5 x 10^-4 M, what is the value of Ksp for Pb(N3)2?
Problem 104
Problem 105a,b
Use the following solubility data to calculate a value of Ksp for each compound. (a) SrF2: 1.03 x 10-3 M (b) CuI: 1.05 x 10-6 M
Problem 105c,d
Use the following solubility data to calculate a value of Ksp for each compound. (c) MgC2O4: 0.094 g/L (d) Zn(CN)2; 4.95 x 10-4 g/L
- If the following solutions are mixed, is the resulting solution acidic, basic, or neutral? (a) 50.0 mL of 0.100 M HBr and 30.0 mL of 0.200 M KOH
Problem 106
- Use the values of Ksp in Appendix C to calculate the molar solubility of the following compounds: (b) Mg(OH)2
Problem 107
- Use the values of Ksp in Appendix C to calculate the solubility of the following compounds (in g/L): (c) Cu3(PO4)2
Problem 108
- Use Le Châtelier’s principle to explain the following changes in the solubility of Ag2CO3 in water. (a) Decrease on addition of AgNO3 (b) Increase on addition of HNO3 (c) Decrease on addition of Na2CO3 (d) Increase on addition of NH3
Problem 109