The solubility of $AgCl$ is $4 \times 10^{-6} \ M$. Find its $K_{sp}$. Also,find its new solubility in the presence of $2 \times 10^{-3} \ M \ CaCl_2$.

Which of the following statement$(s)$ is/are correct.
$A$. The $pH$ of $1 \times 10^{-8} \ M$ aqueous solution of $HCl$ is $8$
$B$. The conjugate base of $H_2PO_4^{\ominus}$ is $HPO_4^{2-}$
$C$. $K_w$ increases with increase in temperature
$D$. When a solution of a weak monoprotic acid is titrated against a strong base,then at the half-neutralization point,$pH = pK_a$.

$pH$ of a resulting solution prepared by mixing $100 \ mL$ $0.1 \ M$ $HCl$ and $200 \ mL$ $0.05 \ M$ $NaOH$ is

What is the $pH$ of the resulting solution when $20 \text{ mL}$ of $\frac{M}{10} \text{ NaOH}$ and $10 \text{ mL}$ of $\frac{M}{10} \text{ H}_2\text{SO}_4$ are mixed together?

If $20 \, mL$ of $0.25 \, N$ strong acid and $30 \, mL$ of $0.2 \, N$ strong base are mixed,then the resulting solution is

$A$ certain weak base has a dissociation constant $2 \times 10^{-5}$. The equilibrium constant for its neutralization reaction with a strong acid is