The correct order of liquefaction of the gases ${\mathrm{NH}}_3, {\mathrm{CO}}_2, {\mathrm{SO}}_2 \mathrm{and} \mathrm{HCl}$is

The variation of vapour pressure with temperature for a liquid was studied by plotting $\mathrm{logP}$ versus $\frac{1}{\mathrm{T}}$ as shown in the Figure. The slope of the line $\tan \left(\mathrm{\theta }\right)$ was found to be $-2 \mathrm{K}$. Then latent heat of vaporisation of the given liquid is

Which values can be obtained from the information represented by the vapour pressure curve of a liquid ?

A. Normal boiling point B. Normal freezing point C. Enthalpy of vaporisation.

The qualitative sketches I, II and III given below show the variation of surface tension with molar concentration of three different aqueous solutions $\mathrm{KCI}, {\mathrm{CH}}_3\mathrm{OH}$ and ${\mathrm{CH}}_3({\mathrm{CH}}_2{)}_{11}{{\mathrm{SO}}_3}^{-} {\mathrm{Na}}^{+}$ at room temperature. The correct assignment of the sketches is