Enthalpy of vaporisation of napthalene is 48.5 kJ/mol and enthalpy of fusion of napthalene is 22.5 kJ/mol, then enthalpy of subtlimation of naphthalene will be

Options

A. `-48.5` kJ/mol
B. `+22.5` kJ/mol
C. 26.0 kJ/mol
D. 71.0kJ/mol

Answer

D

Explanation

Sublimation of naphthalene is
Naphthalene `(s)underset(DeltaH_(f))overset("fusion")(to)` Naphthalene (l)
`underset(DeltaH_(v))overset("Vaporisation")(to)` Naphthalene (g)
`DeltaH_("sublimation")=DeltaH_("fusion")+DeltaH_("vaporisation")`
`=22.5+48.5`
`DeltaH_("sublimation")=71.0` kJ/mol