According to Henry's law,the solubility of a gas in a given volume of liquid increases with increase in

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:

Explain the solubility of a solution formed by a gaseous solute and a liquid solvent.

The Henry's law constant for the solubility of $N_2$ gas in water at $298 \ K$ is $1.0 \times 10^5 \ atm$. The mole fraction of $N_2$ in air is $0.8$. Calculate the number of moles of $N_2$ dissolved in $10 \ moles$ of water at $298 \ K$ and a total pressure of $5 \ atm$.

Which of the following salt's solubility increases appreciably with an increase in temperature?

The partial pressure of ethane over a solution containing $7.14 \times 10^{-3} \ g$ of ethane is $1 \ bar$. If the solution contains $5 \times 10^{-2} \ g$ of ethane,then what shall be the partial pressure of the gas (in $bar$)? (At equal temperature)