Which of the following dissolves in water to give a neutral solution?

Which of the following compounds give a basic solution on hydrolysis?
$(1)$ $NH_4Cl$
$(2)$ $K_2CO_3$
$(3)$ $Na_2B_4O_7 \cdot 10 H_2O$
$(4)$ $NaCl$

Which of the following salt solutions turns red litmus blue?

The degree of hydrolysis of a $0.01 \ M$ ammonium acetate solution is = ........ [ $K_h = 3.175 \times 10^{-5}$ ]

The $pH$ of the solution,when
$(i)$ sodium acetate is dissolved in water.
$(ii)$ ammonium chloride is dissolved in water.

The degree of hydrolysis in hydrolytic equilibrium $A^{-} + H_2O \rightleftharpoons HA + OH^{-}$ at salt concentration of $0.001 \ M$ is $(K_a = 1 \times 10^{-5})$