Question

What is the percentage dissociation of $0.1M$ solution of acetic acid? $(K_a=10^{-5})$

• A. $10\%$
• B. $100\%$
• C. $1\%$
• D. $0.01\%$

Answer 1

Answer: (C)

$\alpha =\sqrt{\frac{K_a}{c}}$ or $\alpha =\sqrt{\frac{10^{-5}}{0.1}}=10^{-2}$
$\%$ dissociation $=10^{-2}\times 100=1\%$