$A$ cylinder contains hydrogen gas at a pressure of $249\; kPa$ and temperature $27^{\circ} C$. Its density is $............. kg/m^{3}$ $(R = 8.3\; J\; mol^{-1} K^{-1})$.

What is the number of molecules in $1 \, litre$ of an ideal gas at $S.T.P.$?

$A$ container holds $13 \, g$ of gas at a temperature of $27^{\circ}C$. If the temperature of the container is raised to $52^{\circ}C$ while keeping the pressure constant,the amount of gas that must be released is ..... $g$.

Two identical glass bulbs are interconnected by a thin glass tube. Initially,both bulbs are at $0^{\circ}C$. $A$ gas is filled in these bulbs. When one bulb is placed in ice $(0^{\circ}C)$ and the other bulb is placed in a hot bath,the pressure of the gas becomes $1.5$ times the initial pressure. The temperature of the hot bath will be ...... $^{\circ}C$.

In the given $(V - T)$ diagram,what is the relation between pressures $P_1$ and $P_2 \,?$

$A$ large flask contains air at $27 \, ^{\circ}C$. In order to expel half the mass of air from the flask, the flask should be heated up to what temperature in $^{\circ}C$?