Statement-$1$: The hydrogen carbonates of the alkali metals are soluble in water, but are less soluble than the corresponding normal carbonates.

Statement-$2$: The hydrogen carbonates of the alkali metals have $H-$bonding.

Statement-$1$ is true, statement-$2$ is true and statement-$2$ is correct explanation for statement-$1$.

Statement-$1$ is true, statement-$2$ is true and statement-$2$ is NOT the correct explanation for statement-$1$.

Statement-$1$ is true, statement-$2$ is false.

Statement-$1$ is false, statement-$2$ is true.