Calculate the hydrolysis constant of the salt containing `NO_(2)^(-)`. Given the `K_(a) " for " HNO_(2) = 4.5 xx 10^(-10)`

Answer

`2.2xx10^(-5)`

Explanation

For the salt containing `NO_(2)^(-)` ion (i.e., salt of weak acid), `K_(b) = (K_(w))/(K_(a))=(10^(-4))/(4.5xx10^(-10))=2.2xx10^(-5)`.