Question

0.2 M solution of formic acid is ionized 3.2$\%$, its ionization constant is

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

$K_a=C{\alpha }^2$
$=0.2\times {\left(\frac{3.2}{100}\right)}^2=2.048\times {10}^{-4}=2.1\times {10}^{-4}$