Question

If a decinormal solution of NaOH is added in a mixture of weak base and its strong salt then in the following condition which option is correct?

(a) Very high change in OH^– ions

(b) High change in OH^– ions

(c) Slight change in OH^– ions

(d) No change in OH^– ions

The question was asked in examination.

Question is from Buffers in portion Introduction to Fermentation Processes & Media for Industrial Fermentation of Bioprocess Engineering

Answer 1

The correct answer is (c) Slight change in OH^– ions

To explain: When a decinormal solution of NaOH is added in a mixture of weak base and its strong salt (e. g.,NH4OH + NH4Cl) then a slight change in OH ion concentration takes place. It means the pH value in these media remains approximately the same and these solutions resist any change of acidity or alkalinity.