Consider the benzoic acid/sodium benzoate buffer described in the previous probl
ID: 1002844 • Letter: C
Question
Consider the benzoic acid/sodium benzoate buffer described in the previous problem. If NaOH is added to this buffer, which of the following changes will occur? A. [benzoic acid] will decrease and [sodium benzoate] will increase. B. [benzoic acid] will increase and [sodium benzoate] will stay the same. C. [benzoic acid] will stay the same and [sodium benzoate] will decrease. D. [benzoic acid] will stay the same and [sodium benzoate] will increase. E. [benzoic acid] will decrease and [sodium benzoate] will stay the same
Explanation / Answer
Benzoate acid (C6H5CO2H) is a weak acid
Benzoic sodium (NaC6H5CO2) is a salt that comes from weak acid (acid Benzoate)
by adding NaOH buffer completely neutralized obtaining sodium benzoate salt to be a weak acid and strong base, where the pH is then equivalent basic. Therefore benzoate and benzoic acid diminish sodium increased.
C6H5CO2H + NaOH en equilibrio NaC6H5CO2 + H2O