Question

Determine the percent dissociation of acetic acid in a $0.1$M solution, if the $\left[H_3{O}^{+}\right]$ is $1\times {10}^{-3}$ mole$/$liter.

• A. $0.01\%$
• B. $0.1\%$
• C. $1.0\%$
• D. $1.5\%$
• E. $2.0\%$

Answer 1

Answer: (C)

$1.0\%$

$C{H}_{3}COOH\rightleftharpoons C{H}_{3}CO{O}^{-}+H^{+}$
Initial $\left[C{H}_{3}COOH\right]=0.1M$
Equilibrium $\left[C{H}_{3}COOH\right]=0.1-xM$
Equilibrium $\left[H_3{O}^{+}\right]=xM=1\times {10}^{-3}mol/L$
The percent dissociation of acetic acid $=\frac{\left[H_3{O}^{+}\right]}{[C{H}_{3}COOH{]}_{initial}}\times 100=\frac{1\times {10}^{-3}}{0.1}\times 100=1.0$