Question

The $pH$ of a $0.01M$ solution of acetic acid whose degree of dissociation $8$% is :

• A. $3.1$
• B. $2.9$
• C. $4.1$
• D. $2.2$

Answer 1

The correct option is A $3.1$

Dissociation of acetic acid gives:

${CH}_{3}COOH+H_{2}O\to C{H}_3{COO}^{-}+H_3{O}^{+}$.

Here since degree of dissociation is $8\%$ i.e. $0.08$.

So, amount of $H_3{O}^{+}$ ions formed $=0.08\times 0.01=0.0008M$.

So, $pH$ of acetic acid will be

$pH=-\log {[H}_3{O}^{+}]pH=-\log \left[0.0008\right]pH=3.1$

So, the correct answer is option A.