Given,

For solid A : ${\log }_{10} \mathrm{P}=4-\frac{2000}{\mathrm{T}}$

For liquid A : ${\log }_{10} \mathrm{P}=3.48-\frac{1500}{\mathrm{T}}$

Here P is in mm of Hg and T in K.

For this reaction the enthalpy of vapourisation and enthalpy of fusion will be temperature independent. The values of enthalpies for this case,

Sublimation enthply, ${\mathrm{\Delta H}}_{\text{sub }}$ = 9.212 kcal/mol.

Enthply of fusion, ${\mathrm{\Delta H}}_{\text{fusion }}$= 2.303 kcal/mol..

Vaporization enthply, ${\mathrm{\Delta H}}_{\text{vap. }}$= 6.909 kcal/moll.