Problem 55c
Blood is buffered by carbonic acid and the bicarbonate ion. Normal blood plasma is 0.024 M in HCO3- and 0.0012 M H2CO3 (pKa1 for H2CO3 at body temperature is 6.1).
c. Given the volume from part (b), what mass of NaOH can be neutralized before the pH rises above 7.8?
Problem 56
The fluids within cells are buffered by H2PO4- and HPO42- . b. Could a buffer system employing H3PO4 as the weak acid and H2PO4- as the weak base be used as a buffer system within cells? Explain.
- Which buffer system is the best choice to create a buffer with pH = 7.20? For the best system, calculate the ratio of the masses of the buffer components required to make the buffer: HC2H3O2/KC2H3O2, HClO2/KClO2, NH3/NH4Cl, or HClO/KClO.
Problem 57
Problem 58
Which buffer system is the best choice to create a buffer with pH = 9.00? For the best system, calculate the ratio of the masses of the buffer components required to make the buffer. HF/KF HNO2/KNO2 NH3/NH4Cl HClO/KClO
Problem 59a
A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine if each addition would exceed the capacity of the buffer to neutralize it. a. 250 mg NaOH
Problem 59b
A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine if each addition would exceed the capacity of the buffer to neutralize it. b. 350 mg KOH
Problem 59c
A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine if each addition would exceed the capacity of the buffer to neutralize it. c. 1.25 g HBr
Problem 59d
A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine if each addition would exceed the capacity of the buffer to neutralize it. d. 1.35 g HI
Problem 60
A 1.0-L buffer solution is 0.125 M in HNO2 and 0.145 M in NaNO2. Determine the concentrations of HNO2 and NaNO2 after the addition of each substance: a. 1.5 g HCl b. 1.5 g NaOH c. 1.5 g HI
Problem 61a
The graphs labeled (a) and (b) show the titration curves for two equal-volume samples of monoprotic acids, one weak and one strong. Both titrations were carried out with the same concentration of strong base.
(i) What is the approximate pH at the equivalence point of each curve?
Problem 61b
The graphs labeled (a) and (b) show the titration curves for two equal-volume samples of monoprotic acids, one weak and one strong. Both titrations were carried out with the same concentration of strong base.
(ii) Which graph corresponds to the titration of the strong acid and which one to the titration of the weak acid?
- Two 25.0-mL samples, one 0.100 M HCl and the other 0.100 M HF, are titrated with 0.200 M KOH. a. What is the volume of added base at the equivalence point for each titration?
Problem 62
Problem 62b
Two 25.0-mL samples, one 0.100 M HCl and the other 0.100 M HF, are titrated with 0.200 M KOH. b. Is the pH at the equivalence point for each titration acidic, basic, or neutral?
Problem 62c
Two 25.0-mL samples, one 0.100 M HCl and the other 0.100 M HF, are titrated with 0.200 M KOH. c. Which titration curve has the lower initial pH?
Problem 62d
Two 25.0-mL samples, one 0.100 M HCl and the other 0.100 M HF, are titrated with 0.200 M KOH.
d. Sketch each titration curve.
Problem 63a
Two 20.0-mL samples, one 0.200 M KOH and the other 0.200 M CH3NH2, are titrated with 0.100 M HI. a. What is the volume of added acid at the equivalence point for each titration?
Problem 63b
Two 20.0-mL samples, one 0.200 M KOH and the other 0.200 M CH3NH2, are titrated with 0.100 M HI. b. Is the pH at the equivalence point for each titration acidic, basic, or neutral?
Problem 63c
Two 20.0-mL samples, one 0.200 M KOH and the other 0.200 M CH3NH2, are titrated with 0.100 M HI. c. Which titration curve has the lower initial pH?
Problem 63d
Two 20.0-mL samples, one 0.200 M KOH and the other 0.200 M CH3NH2, are titrated with 0.100 M HI. d. Sketch each titration curve.
Problem 64b
The graphs labeled (a) and (b) show the titration curves for two equal-volume samples of bases, one weak and one strong. Both titrations were carried out with the same concentration of strong acid.
(ii) Which graph corresponds to the titration of the strong base and which one to the weak base?
Problem 65c
Consider the curve shown here for the titration of a weak monoprotic acid with a strong base and answer each question.
c. At what volume of added base does pH = pKa?
Problem 65d
Consider the curve shown here for the titration of a weak monoprotic acid with a strong base and answer each question.
d. At what volume of added base is the pH calculated by working an equilibrium problem based on the concentration and Kb of the conjugate base?
Problem 66a
Consider the curve shown here for the titration of a weak base with a strong acid and answer each question.
a. What is the pH and what is the volume of added acid at the equivalence point?
Problem 66c
Consider the curve shown here for the titration of a weak base with a strong acid and answer each question.
c. At what volume of added acid does pH = 14 - pKb?
Problem 66d
Consider the curve shown here for the titration of a weak base with a strong acid and answer each question.
d. At what volume of added acid is the pH calculated by working an equilibrium problem based on the concentration and Ka of the conjugate acid?
Problem 67a
Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine each quantity. a. the initial pH
Problem 67b
Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine each quantity. b. the volume of added base required to reach the equivalence point
Problem 67c
Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine each quantity. c. the pH at 10.0 mL of added base
Problem 67d
Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine each quantity. d. the pH at the equivalence point
Problem 67e
Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine each quantity. e. the pH after adding 5.0 mL of base beyond the equivalence point
Ch.18 - Aqueous Ionic Equilibrium