At constant temperature, the pressure of a gas is decreased by $20 \%$. What is the percentage change in volume?

$A$ container $A$ contains an ideal gas at pressure $P$,volume $V$,and temperature $T$. $A$ second container $B$ contains the same gas at pressure $2P$,volume $2V$,and temperature $\frac{T}{2}$. The ratio of the mass of gas in $A$ to that in $B$ is:

For a monoatomic gas at constant pressure,the $V \rightarrow T$ graph is . . . . . .

If the volume of a given mass of a gas is increased four times,and the temperature is raised from $27^{\circ}C$ to $127^{\circ}C$,what happens to its elasticity?

$A$ container $X$ has a volume double that of container $Y$,and both are connected by a thin tube. Both contain the same ideal gas. The temperature of $X$ is $200\,K$ and that of $Y$ is $400\,K$. If the mass of the gas in $X$ is $m$,then the mass of the gas in $Y$ will be:

Two different masses $m$ and $3m$ of an ideal gas are heated separately in a vessel of constant volume. The pressure $P$ versus absolute temperature $T$ graphs for these two cases are shown in the figure. The ratio of the slopes of curves $B$ to $A$ is