$A$ gas $X$ is dissolved in water at $2 \ bar$ pressure. Its mole fraction in the solution is $0.02$. Find the mole fraction of water in the solution when the pressure of the gas is doubled at the same temperature.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Helium is used to dilute oxygen in diving apparatus.
Reason $R$: Helium has high solubility in $O_2$.
In the light of the above statements,choose the correct answer from the options given below:

Assertion : Iodine is more soluble in water than in carbon tetrachloride.
Reason : Iodine is a polar compound.

Calculate the quantity of $CO_2$ required to prepare $1 \,L$ of soda water when the soda water is packed under $2 \,atm$ of $CO_2$. [Henry's law constant for $CO_2$ is $1.67 \times 10^8 \,Pa$] (in $\,g$)

Solubility of $N_2$ gas in water at $25\,^{\circ}C$ and $0.78\, atm$ is $5.4 \times 10^{-4}\, M$. Calculate Henry's law constant for $N_2$ in water at $25\,^{\circ}C$.

At $298 \ K$,Henry's law constant for $CO_2$ in water is $1.67 \times 10^8 \ Pa$. At $298 \ K$,the quantity of $CO_2$ in $1000 \ mL$ of soda water when packed at $1.67 \times 10^2 \ kPa$ $CO_2$ pressure in $mol \ L^{-1}$ is: (water density $= 1.0 \ g \ cm^{-3}$)