Identify the correct statements from the following.
$I$. Glass is an extremely viscous liquid.
$II$. Increase in temperature decreases the surface tension of liquids.
$III$. Compressibility factor for an ideal gas is zero.

Equal masses of $CH_4$ and $H_2$ are mixed in an empty container at $25\,^oC$. The fraction of the total pressure exerted by methane is

At constant temperature,$200 \ cm^3$ of $N_2$ at $720 \ mm$ pressure and $400 \ cm^3$ of $O_2$ at $750 \ mm$ pressure are taken in a $1 \ L$ flask. What will be the total pressure of the mixture in $mm$?

Two balloons $A$ and $B$ containing $0.2 \ mol$ and $0.1 \ mol$ of helium at room temperature and $2.0 \ atm$,respectively,are connected. When equilibrium is established,the final pressure of $He$ in the system is $.... \ atm$.

$\frac{1}{24.63}$ mole of an ideal mono-atomic gas undergoes a reversible process for which $PV^3 = C$,where $C$ $(L^2 \cdot atm)$ is a constant. The gas expands from an initial volume of $1 \ L$ and an initial temperature of $300 \ K$ to a final volume of $2 \ L$. The heat lost to the surroundings by the gas is ...... $J$.

The normal boiling point of water is $373 \ K$ (at $760 \ mm$). The vapor pressure of water at $298 \ K$ is $23 \ mm$. If the enthalpy of vaporization of water is $40.656 \ kJ/mol$,then the boiling point of water at $23 \ mm$ pressure will be ........... $K$.