Arrange the aqueous solutions of the following salts in the increasing order of $pH$: $CuSO_4$ $(I)$,$NaCN$ $(II)$,$KCl$ $(III)$.

Calculate the $pH$ of a $0.1 \ M$ sodium acetate solution. Given: $K_a$ for $CH_3COOH = 1.8 \times 10^{-5}$.

Classify salts based on their hydrolysis and provide examples for each category.

Calculate the hydrolysis constant $(K_h)$ for a salt containing $NO_2^-$. Given that the dissociation constant $(K_a)$ for $HNO_2$ is $4.5 \times 10^{-4}$ and the ionic product of water $(K_w)$ is $1.0 \times 10^{-14}$.

When $CuSO_4$ is hydrated,it becomes:

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?