Question

What is the percent ionization of a 0.01 M $HCN$ solution? Given: $K_a=6.4\times {10}^{-9}$

• A. $8\times {10}^{-4}$ %
• B. $0.08$%
• C. $8\times {10}^{-3}$%
• D. $0.8$%

Answer 1

Answer: (A)

$8\times {10}^{-4}$ %

$\alpha =\sqrt{\frac{K_a}{C}}$

$\alpha$ =$\sqrt{\frac{6.4\times {10}^{-9}}{0.01}}$ = $8\times {10}^{-4}$

Option $A$ is correct.