Question

Which one of the following is not a buffer solution?

• A. $C{H}_{3}COOH/C{H}_{3}COONa$
• B. $HCl/NaCl$
• C. $HCOOH/HCOONa$
• D. $N{H}_{4}OH/N{H}_{4}Cl$

Answer 1

The correct option is B $HCl/NaCl$

A solution of weak acid and weak base with its conjugate salt in water is called as Buffer solution.
$C{H}_{3}COOHandHCOOH$ are weak acids. Again $N{H}_{4}OH$ is a weak base.
All the option are buffer solution is an aqueous solution consisting of a mixture of weak acid and its conjugate base or vice-versa except option (b) which have HCl a strong acid and a salt of strong acid$\left(HCl\right)$ and base $\left(NaOH\right)$ i.e. $NaCl$