If the $pK_a$ value of $CH_3COOH$ is $4.74$,then the $pH$ value of $0.1 \ M \ CH_3COONa$ 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?

The $pH$ of $0.1 \, M$ aqueous solutions of $NaCl$,$CH_3COONa$ and $NH_4Cl$ will follow the order:

The $pH$ of a $0.02 \ M \ NH_4Cl$ solution will be [given $K_b \ (NH_4OH) = 10^{-5}$ and $\log \ 2 = 0.301$ ]

For which of the following pairs of salts is the degree of hydrolysis independent of dilution?

The $pH$ of the solution obtained on neutralization of $40 \ mL \ 0.1 \ M \ NaOH$ with $40 \ mL \ 0.1 \ M \ CH_3COOH$ is