The strength of 50 volume solution of hydrogen peroxide is ______ $\mathrm{g} / \mathrm{L}$ (Nearest integer).

The density of $3 \mathrm{M}$ solution of $\mathrm{NaCl}$ is $1.0 \mathrm{~g} \mathrm{~mL}^{-1}$. Molality of the solution is ____________ . (Nearest integer).

5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0.1 M solution? _____________

Given : Molar Mass of Na, O and H is 23, 16 and 1 g mol$^{-1}$ respectively

$20 \mathrm{~mL}$ of $0.02 \,\mathrm{M} \,\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ solution is used for the titration of of solution in the acidic medium.

Chlorophyll extracted from the crushed green leaves was dissolved in water to make $2 \mathrm{~L}$ solution of Mg of concentration $48\, \mathrm{ppm}$. The number of atoms of $\mathrm{Mg}$ in this solution is atoms. The value of is ___________. (Nearest Integer)

The moles of methane required to produce 81 g of water after complete combustion is _____________ $\times$ 10^$-$2 mol. [nearest integer]