Absolute zero $(0\, K)$ is that temperature at which

$O_2$ gas is filled in a cylinder. If the pressure is doubled and the temperature is quadrupled,what will be the factor by which the density changes?

$A$ container $A$ contains a gas at pressure $P$,volume $V$,and temperature $T$. Another container $B$ contains a gas at pressure $2P$,volume $V/4$,and temperature $2T$. The ratio of the number of molecules in container $A$ to that in container $B$ is:

Under constant temperature,the graph between $P$ and $1/V$ is:

$A$ certain amount of gas has a volume of $12 \, L$ at a pressure of $3 \, atm$. If the temperature remains constant,what pressure in $atm$ must be applied to reduce its volume to $9 \, L$?

An oxygen cylinder of volume $30 \; L$ has an initial gauge pressure of $15 \; atm$ and a temperature of $27 \; ^{\circ}C$. After some oxygen is withdrawn from the cylinder,the gauge pressure drops to $11 \; atm$ and its temperature drops to $17 \; ^{\circ}C$. Estimate the mass (in $kg$) of oxygen taken out of the cylinder ($R = 8.31 \; J \; mol^{-1} K^{-1}$,molecular mass of $O_{2} = 32 \; u$).