An aqueous solution of ethanol has strength of $50 \mathrm{g}/\mathrm{L}$. Calculate the weight/weight $(\mathrm{w}/\mathrm{w})\%$ concentration. Given density of pure ethanol $= 0.8 \mathrm{g}/\mathrm{ml}$. And density solution $1 \mathrm{g}/\mathrm{ml}$.

The molality of a $10\%(\mathrm{v}/\mathrm{V})$ solution of di-bromine solution in ${\mathrm{CCl}}_4$ (carbon tetrachloride) is $\mathrm{x}$ '. $\mathrm{x}=$ $\_\_\_\_\_\times {10}^{-2}\mathrm{M}$. (Nearest integer)

[Given : molar mass of ${\mathrm{Br}}_2=160 \mathrm{g} {\mathrm{mol}}^{-1}$

atomic mass of $\mathrm{C}=12 \mathrm{g} {\mathrm{mol}}^{-1}$

atomic mass of $\mathrm{Cl}=35.5 \mathrm{g} {\mathrm{mol}}^{-1}$

density of dibromine $=3.2 \mathrm{g} {\mathrm{cm}}^{-3}$

density of $\left.{\mathrm{CCl}}_4=1.6 \mathrm{g} {\mathrm{cm}}^{-3}\right]$

The density of $3\mathrm{M}$ solution of $\mathrm{NaCl}$ is $1.0 \mathrm{g} {\mathrm{mL}}^{-1}$. Molality of the solution is $\_\_\_\_\_\_\times {10}^{-2} \mathrm{m}$ (Nearest integer).

Given: Molar mass of $\mathrm{Na}$ and $\mathrm{Cl}$ is $23$ and $35.5 \mathrm{g}$ ${\mathrm{mol}}^{-1}$ respectively.

$1.46 \mathrm{g}$ of a biopolymer dissolved in a $100 \mathrm{mL}$ water at $300 \mathrm{K}$ exerted an osmotic pressure of $2.42\times {10}^{-3}\mathrm{bar}$ 

The molar mass of the biopolymer is $-\times {10}^4 \mathrm{g}$ ${\mathrm{mol}}^{-1}.$ (Round off to the Nearest Integer)
[Use: $\mathrm{R}=0.083 \mathrm{L}$ bar $\left.{\mathrm{mol}}^{-1}{ \mathrm{K}}^{-1}\right]$