Question

Degree of dissociation of $C{H}_{3}COOH$ and $N{H}_{4}OH$ are the same. If $0.01$ M solution of $C{H}_{3}COOH$ has $pH=4.0$; then $pH$ of $0.01$ M $N{H}_{4}OH$ will be:

• A. $4$
• B. $7$
• C. $10$
• D. $14$

Answer 1

The correct option is C $10$

The degree of dissociation of acetic acid and ammonium hydroxide are the same. Their molar concentrations are also the same.

Hence, the hydrogen ion concentration of the acetic acid solution is equal to the hydroxide ion concentration of ammonium acetate.

Thus the $pH$ of the acetic acid solution is equal to the $pOH$ of ammonium hydroxide solution. It is equal to $4.0$.

The pH of ammonium hydroxide ion solution will be $14.0-4.0=10.0$.

Option C is correct.