During the evaporation of a liquid,$..........$

The rate of diffusion of methane at $1.0 \ atm$ pressure is twice that of another gas '$X$' kept at $1.45 \ atm$. The molecular weight of the gas '$X$' is
[$T$ kept constant]

The radius of the $Na^{+}$ ion is $95 \ pm$ and that of $Cl^{-}$ ion is $181 \ pm$. Predict the coordination number of $Na^{+}$ in $NaCl$.

Which of the following statements is incorrect?
$1$. The property of liquid drops to have minimum surface area is called surface tension.
$2$. Surface tension of liquids decreases with rise in temperature.
$3$. The $SI$ unit of surface tension is $N \ m^{-1}$.
$4$. Magnitude of surface tension is less,when there is strong attractive force between the molecules.

$\frac{1}{24.63}$ 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 ...... $J$.

$A$ beaker containing a mixture of liquid $A$ and liquid $B$,in equilibrium with each other,is cooled very slowly. If point '$D$' on the graph is where solidification of both liquids is complete,how many different phases co-exist along line '$C D$' if freezing points of liquid $B$ and liquid $A$ are $-25^{\circ} C$ and $-78^{\circ} C$ respectively?