Free residual chlorine concentration in water was measured to be $2 \mathrm{mg} / \mathrm{l}$ (as $\mathrm{Cl}_2$ ). The pH of water is 8.5. By using the chemical equation given below, the HOCl concentration (in $\mu$ moles $/ \mathrm{l}$ ) in water is $\qquad$ (round off to one decimal place).

$$ \mathrm{HOCl} \rightleftharpoons \mathrm{H}^{+}+\mathrm{OCl}^{-}, \mathrm{pK}=7.50 $$

Atomic weight: Cl(35.5)

The following table gives various components of Municipal Solid Waste (MSW) and a list of treatment/separation techniques.

The CORRECT match is

A 100 mg of HNO₃ (strong acid) is added to water, bringing the final volume to 1.0 liter. Consider the atomic weights of H, N, and O, as 1 g/mol. 14 g mol. and 16 g/mol, respectively. The final pH of this water is (Ignore the dissociation of water.)