At $NTP$,the mass of one litre of air is $1.293 \; g$. The value of the specific gas constant will be ...... $J/(K \cdot g)$.

Air is filled at $60^oC$ in a vessel with an open mouth. The vessel is heated to a temperature $T$ so that $1/4^{th}$ of the air escapes. Assuming the volume of the vessel remains constant,the value of $T$ is ....... $^oC$.

$A$ gas at the temperature $250\,K$ is contained in a closed vessel. If the gas is heated through $1\,K,$ then the percentage increase in its pressure will be ...... $\%$

In the given pressure $(P)$ - absolute temperature $(T)$ graph of an ideal gas,the relation between volumes $V_1, V_2, V_3$ and $V_4$ is

$A$ thin tube sealed at both ends is $100 \ cm$ long. It lies horizontally, the middle $20 \ cm$ containing mercury and two equal ends containing air at standard atmospheric pressure. If the tube is now turned to a vertical position, by what amount will the mercury be displaced? (Given: cross-section of the tube can be assumed to be uniform) ........ $cm$

The gas in a vessel is subjected to a pressure of $20 \ atm$ at a temperature of $27^{\circ}C$. If one-half of the gas is released from the vessel and the temperature of the remaining gas is raised by $50^{\circ}C$,the final pressure of the gas in the vessel is ....... $atm$.