The pressure $Vs$ temperature graph of an ideal gas is shown in the figure. If the density of the gas at point $A$ is $\rho _0$,what will be the density at point $B$?

$A$ gas is collected over water at $25^{\circ}C$. The total pressure of the moist gas was $735 \, mm$ of mercury. If the aqueous vapour pressure at $25^{\circ}C$ is $23.8 \, mm$,then the pressure of the dry gas is..... $mm$.

Equal molar amounts of $H_2$ and $He$ are placed in two separate containers of equal volume at the same temperature. Their molar masses are $2$ and $4$ respectively. If the pressure of $H_2$ gas is $4 \ atm$,what will be the pressure of $He$ gas in atmospheres?

The given figure represents two isobaric processes for the same mass of an ideal gas. Then:

Pressure of a gas of constant volume at $20^{\circ} C$ is $90 \ cm$ of $Hg$. At what temperature the pressure would change to $75 \ cm$ of $Hg$ (in $^{\circ} C$)?

The mass of oxygen gas occupying a volume of $11.2 \text{ litres}$ at a temperature $27^{\circ}C$ and a pressure of $760 \text{ mm}$ of mercury in kilograms is $[$ Molecular weight of oxygen $= 32]$