Use the following information to answer both parts. A buffer solution is 0.050 M
ID: 509565 • Letter: U
Question
Use the following information to answer both parts.
A buffer solution is 0.050 M in benzoic acid (HC7H5O2) and 0.150 M in sodium benzonate (NaC7H5O2). For benzoic acid, ka = 6.5 x 10^-5.
The acid and base components of the buffer are ____ and _____, respectively.
A. NaC7H5O2, HC7H5O2 B. HC7H5O2, NaC7H5O2 C. NaHC7H5O2, C7H5O2^- D. ^+HC7H5O2, NaC7H5O2 E, none of the above
Based on the information for the previous part, the pH of the buffer solution is given by:
I. pH= pka + log [base]/[acid]
II. pH= -pka + log [base]/[acid]
III. pH= -log (6.5 x 10^-5) + log(0.150/0.050) = 4.66
IV. pH= log(6.5 x 10^-5) + log (0.150/0.050) = 4.66
A. I B. II and IV C. III D. I and III E. II
Explanation / Answer
Acid component fot he buffer is clearly the Benzoic acid
The base component is the Sodium Benzoate,
Best answer is
B. HC7H5O2, NaC7H5O2
Based on this info....
The pH is given by
pH = pKa + log(base/Acid)
pH = -log(6.5*10^-5) + log(0.15 / 0.05)
best answer is I and III (D)