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

The pressure of an $LPG$ gas cylinder is $14.9 \ bar$,which is considered safe. If the pressure is $12 \ bar$ at $27 \ ^oC$,at what temperature will the cylinder blast (in $K$)?

At the same temperature,gas $A$ is taken in a $0.5 \, dm^3$ flask and gas $B$ is taken in a $1 \, dm^3$ flask. If the density of $A$ is $3.0 \, g \, dm^{-3}$ and that of $B$ is $1.5 \, g \, dm^{-3}$,and the molar mass of $A$ is $1/2$ of $B$,what is the ratio of the pressures exerted by the gases?

In an experiment during the analysis of a carbon compound,$145 \ L$ of $H_2$ was collected at $760 \ mm \ Hg$ pressure and $27 \ ^oC$ temperature. The mass of $H_2$ is nearly $....... \ g$.

In the gas equation $PV = nRT$,the universal gas constant $R$ depends on:

$A$ hot air balloon has a volume of $2000 \text{ dm}^3$ at $99^\circ\text{C}$. What is the new volume if the air in the balloon cools to $80^\circ\text{C}$ (in $\text{ dm}^3$)?