The specific gravity of ${\mathrm{CCl}}_4$, vapour at $0°\mathrm{C}$ and $76 \mathrm{cm}$ $\mathrm{Hg}$ in $\mathrm{grams}/\mathrm{litre}$ is:

A sample of natural gas is $85.2\%$ of methane (${\mathrm{CH}}_4$) and $14.8\%$ of ethane (${\mathrm{C}}_2{\mathrm{H}}_6$) by mass. What would be the density $\left(\mathrm{in} \mathrm{g}/\mathrm{L}\right)$ of this mixture at $18°\mathrm{C}$ and $748 \mathrm{mmHg}$?

Answer by rounding off up to two places of decimals.

The vapour pressure of water at $20°\mathrm{C}$ is $17.5 \mathrm{mm} \mathrm{Hg}$. Calculate the mass of water (in mg) per litre of air at $20°\mathrm{C}$ and $45\%$ relative humidity. $\left(\mathrm{R}=0.0821 \mathrm{atm} \mathrm{L} {\mathrm{mol}}^{-1} {\mathrm{K}}^{-1}\right)$

Answer correct up to two places of decimals.

The composition of the equilibrium mixture ${\mathrm{Cl}}_2\rightleftharpoons 2\mathrm{Cl}$, which is attained at $1200°\mathrm{C},$ is determined by measuring the rate of effusion through a pinhole. It is observed that at $1.80 \mathrm{mmHg}$ pressure, the mixture effuses $1.16$ times as fast as krypton effuses under the same conditions. Calculate the fraction of chlorine molecules dissociated into atoms. (Atomic weight of $\mathrm{Kr}=84$)

Round off your answer up to two places of decimals.