Which of the following gases is not easily soluble in water?

$X \ mL$ of $H_2$ gas effuse through a hole in a container in $5 \ seconds$. The time taken for the effusion of the same volume of the gas specified below under identical conditions is

Equal amounts of two gases of molecular weights $4$ and $40$ are mixed. The pressure of the mixture is $1.1 \ atm$. What will be the partial pressure of the lighter gas in the mixture (in $atm$)?

$A$ $10 \ L$ vessel contains $1 \ mole$ of an ideal gas with pressure of $P \ atm$ and temperature of $T \ K$. The vessel is divided into two equal parts. The pressure (in $atm$) and temperature (in $K$) in each part is respectively:

The temperature at which the vapour pressure of a liquid becomes equal to the atmospheric pressure is known as:

$A$ sample of air contains $N_2$ and $O_2$ saturated with water vapor,with a total pressure of $640 \ torr$. If the water vapor pressure is $40 \ torr$ and the molar ratio of $N_2$ to $O_2$ is $3 : 1$,what is the partial pressure of $N_2$ in the sample in $torr$?