Which of the following salts does not undergo hydrolysis in water?

If the dissociation constant of $HCN$ is $10^{-7}$,what are the values of $pH$,$h$ (degree of hydrolysis),and $[OH^-]$ for a $10^{-3} \ M$ solution of $KCN$,respectively?

In the equilibrium $A^{-} + H_{2}O \rightleftharpoons HA + OH^{-}$ $(K_{a} = 1.0 \times 10^{-5})$,the degree of hydrolysis of a $0.001 \ M$ solution of the salt is:

Consider the following aqueous solutions:
$(1)$ $FeCl_3$ is basic
$(2)$ $NH_4Cl$ is acidic
$(3)$ $NaCN$ is acidic
$(4)$ $Na_2CO_3$ is basic
Which of the following statements is $NOT$ correct?

If the base ionization constant $(K_b)$ of hydrazine $(N_2H_4)$ is $9.6 \times 10^{-9}$,what is the percentage of hydrolysis of a $0.1 \ M$ solution of the salt $N_2H_5Cl$?

Calculate $K_h$ and $pH$ of $0.1 \ M$ $NH_4Cl$ solution. [ $K_w = 1 \times 10^{-14}$,$K_{NH_4OH} = 1.75 \times 10^{-5}$ ]