What do the gas laws,such as Boyle's law,Charles's law,etc.,state?

If the density of a gas at $27\,^{\circ}C$ and $2\, atm$ is $5.46\, g/L$,then calculate the density of the gas at $STP$. (in $, g/L$)

To an evacuated vessel with a movable piston under an external pressure of $1 \ atm$,$0.1 \ mol$ of $He$ and $1.0 \ mol$ of an unknown compound (vapour pressure $0.68 \ atm$ at $0^{\circ} C$) are introduced. Considering ideal gas behaviour,the total volume (in litres) of the gases at $0^{\circ} C$ is close to:

$A$ container of volume $2.24 \, L$ can withstand a maximum pressure of $2 \, atm$ at $298 \, K$ before exploding. The maximum amount of nitrogen (in $g$) that can be safely put in this container at this temperature is closest to

At $25 \, ^\circ C$,a $3.7 \, g$ gas occupies the same volume as $0.184 \, g$ of $H_2$ gas at $17 \, ^\circ C$ under the same pressure. What is the molar mass of the gas?

What is the weight of $CH_4$ gas in a $9 \ L$ cylinder at $27 \ ^oC$ temperature and $1 \ atm$ pressure in $g$?