Question

For two weak acids A and B, the ratio of their percent ionization is 4:9. The ratio of their K_a would be-

• A. 4:9
• B. 2:3
• C. 16:81
• D. 3:2

Answer 1

Answer: (C)

$K_a\propto c{\alpha }^2$

$\therefore \frac{K_{a_1}}{K_{a_2}}=\frac{{\alpha }_1^2}{{\alpha }_2^2}$

$=\frac{4^2}{9^2}=\frac{16}{81}$