When $K_2O$ is added to water,the solution becomes basic because it contains the concentration of which of the following?

Which one of the following statements is not correct?

Which one of the following ionic species has the greatest proton affinity to form a stable compound?

The dissociation constants of two acids $HA_1$ and $HA_2$ are $3.14 \times 10^{-4}$ and $1.96 \times 10^{-5}$ respectively. The relative strength of the acids will be approximately:

The conjugate acid of $NH_3$ is

In the reaction $HNO_3 + H_2O \rightleftharpoons H_3O^{+} + NO_3^{-}$,the conjugate base of $HNO_3$ is = .......