Question

The $pH$ of a $0.1M$ aqueous solution of a weak acid $(HA)$ is $3$ . What is its degree of dissociation?

• A. $1\%$
• B. $10\%$
• C. $50\%$
• D. $25\%$

Answer 1

Answer: (A)

As $pH=3$
So $\left[H^{+}\right]=1\times 10^{-3}$
$\alpha =\left[H^{+}\right]/C$
$=1\times 10^{-3}/0.1$
$=0.01$ $\alpha \%=1\%$