Identify the weak acid-weak base salt from the following.

The aqueous solution of disodium hydrogen phosphate $(Na_2HPO_4)$ is:

The degree of hydrolysis of a $0.1 \ M$ solution of $ArNH_3^+ Cl^-$ is $0.01$. Find the degree of hydrolysis in a $0.4 \ M$ solution of $ArNH_3^+ Cl^-$.

Ionization constants for $CH_3COOH$ and $HCN$ are respectively $1.8 \times 10^{-5}$ and $7.2 \times 10^{-10}$. The degree of hydrolysis of $0.1 \ M \ KCN$ $(h_1)$ and $0.1 \ M \ CH_3COOK$ $(h_2)$ follows the order :

The solution of the salt formed from a strong acid and a weak base,$FeCl_3$,is:

Which of the following produce an alkaline solution when dissolved in water?
$(i)$ Borax
$(ii)$ Potash alum
$(iii)$ $Na_2CO_3$
$(iv)$ $NH_4NO_3$