Which of the following volume $(V)$-temperature $(T)$ plots represents the behaviour of one mole of an ideal gas at one atmospheric pressure?

What will be the pressure of the gaseous mixture when $0.5 \, L$ of $H_{2}$ at $0.8 \, bar$ and $2.0 \, L$ of dioxygen at $0.7 \, bar$ are introduced in a $1 \, L$ vessel at $27^{\circ} C$ (in $, bar$)?

$A$ gas sample of $1.47 \ L$ was collected over water at $30 \ ^\circ C$ and $744 \ mm \ Hg$ pressure. If the weight of the gas is $1.98 \ g$,what is the molar mass of the gas? (Assume the vapor pressure of water at $30 \ ^\circ C$ is $31.8 \ mm \ Hg$)

At $STP$,$0.50 \ mol$ $H_2$ gas and $1.0 \ mol$ $He$ gas:

$A$ vessel of volume $1.2 \, L$ contains a gas at $1000 \, torr$ pressure. Another vessel of volume $3.8 \, L$ contains the same gas at $500 \, torr$ pressure. If both vessels are connected by a tube of negligible volume,what will be the resultant pressure in $torr$ when equilibrium is established?

If $4 \ g$ of oxygen diffuses through a fine hole,how many grams of hydrogen will diffuse under the same conditions?