Design a buffer that has a pH of 5.61 using one of the weak base/conjugate acid systems shown below. Weak Base Kb Conjugate Acid Ka pka CH3NH2 4.2 x 10-4 CH3NH3* 10.62 2.4 x 10-11 1.7 x 10-8 C6H1503N 5.9 x 10-7 C6H1503NH+ 7.77 C5H5N 1.5 x 10-⁹ C5H5NH+ 6.7 x 10-6 5.17 How many grams of the chloride salt of the conjugate acid must be combined with how many grams of the weak base, to produce 1.00 L of a buffer that is 1.00 M in the weak base? grams chloride salt of conjugate acid = grams weak base =

Design a buffer that has a pH of 5.61 using one of the weak base/conjugate acid systems shown below. Weak Base Kb Conjugate Acid Ka pka CH3NH2 4.2 x 10-4 CH3NH3* 10.62 2.4 x 10-11 1.7 x 10-8 C6H1503N 5.9 x 10-7 C6H1503NH+ 7.77 C5H5N 1.5 x 10-⁹ C5H5NH+ 6.7 x 10-6 5.17 How many grams of the chloride salt of the conjugate acid must be combined with how many grams of the weak base, to produce 1.00 L of a buffer that is 1.00 M in the weak base? grams chloride salt of conjugate acid = grams weak base =

Chemistry: An Atoms First Approach

2nd Edition

ISBN:9781305079243

Author:Steven S. Zumdahl, Susan A. Zumdahl

Publisher:Steven S. Zumdahl, Susan A. Zumdahl

Chapter14: Acid- Base Equilibria

Section: Chapter Questions

Problem 4RQ: A good buffer generally contains relatively equal concentrations of weak acid and conjugate base. If...

See similar textbooks

Similar questions

A buffer is composed of formic acid and its conjugate base, the formate ion. (a) What is the pH of a solution that has a formic acid concentration of 0.050 M and a sodium formate concentration of 0.035 M? (b) What must the ratio of acid to conjugate base be to have a pH value 0.50 units higher than the value calculated in part (a)?
A buffer solution that is 0.100 M acetate ion and 0.100 M acetic acid is prepared. (a) Calculate the initial pH, final pH, and change in pH when 1.00 mL of 1.00 M NaOH is added to 100.0 mL of the buffer. (b) Calculate the initial pH, final pH, and change in pH when 1.00 mL of 1.00 M NaOH is added to 100.0 mL pure (pH 7.00) water.
A buffer is prepared using the butyric acid/butyrate (HC4H7O2/C4H7O2)acid-base pair. The ratio of acid to base is 2.2 and Ka for butyric acid is1.54105. (a) What is the pH of this buffer? (b) Enough strong base is added to convert 15% of butyric acid to the butyrate ion. What is the pH of the resulting solution? (c) Strong acid is added to the buffer to increase its pH. What must the acid/base ratio be so that the pH increases by exactly one unit (e.g., from 2 to 3) from the answer in (a)?
What is the pH of a buffer that is 0.175 M in a weak acid and 0.200 M in the acids conjugate base? The acids ionization constant is 5.7 104.
Repeat the procedure in Exercise 61, but for the titration of 25.0 mL of 0.100 M pyridine with 0.100 M hydrochloric acid (Kb for pyridine is 1.7 109). Do not calculate the points at 24.9 and 25.1 mL.
Consider 1.0 L of a solution that is 0.85 M HOC6H5 and 0.80 M NaOC6H5. (Ka for HOC6H5 = 1.6 1010.) a. Calculate the pH of this solution. b. Calculate the pH after 0.10 mole of HCl has been added to the original solution. Assume no volume change on addition of HCl. c. Calculate the pH after 0.20 mole of NaOH has been added to the original buffer solution. Assume no volume change on addition of NaOH.
An aqueous solution contains dissolved C6H5NH3Cl and C6H5NH2. The concentration of C6H5NH2 is 0.50 M and pH is 4.20. a. Calculate the concentration of C6H5NH3+ in this buffer solution. b. Calculate the pH after 4.0 g NaOH(s) is added to 1.0 L of this solution. (Neglect any volume change.)
The titration curves for two acids with the same base are shown on this graph. (a) Which is the curve for the weaker acid? Explain your choice. (b) Give the approximate pH at the equivalence point for the titration of each acid. (c) Explain why the pH at the equivalence point differs for each acid. (d) Explain why the starting pH values of the two acids differ. (e) Which indicator or indicators, phenolphthalein, bromthymol blue, or methyl red, could be used for the titration of Acid 1? For the titration of Acid 2? Explain your choices.
2. If an acetic acid/sodium acetate buffer solution is prepared from 100. mL of 0.10 M acetic acid what volume of 0.10 M sodium acetate must be added to have a pH of 4.00? 100. mL 50. mL 36 mL 18 mL
A good buffer generally contains relatively equal concentrations of weak acid and conjugate base. If you wanted to buffer a solution at pH = 4.00 or pH = 10.00, how would you decide which weak acidconjugate base or weak baseconjugate acid pair to use? The second characteristic of a good buffer is good buffering capacity. What is the capacity of a buffer? How do the following buffers differ in capacity? How do they differ in pH? 0.01 M acetic acid/0.01 M sodium acetate 0.1 M acetic acid/0.1 M sodium acetate 1.0 M acetic acid/1.0 M sodium acetate