Question

Enthalpy of sublimation of a substance is equal to

• A. enthalpy of fusion + enthalpy of vapourisation
• B. enthalpy of fusion
• C. enthalpy of vapourisation
• D. twice the enthalpy of vapourisation

Answer 1

Answer: (A)

enthalpy of fusion + enthalpy of vapourisation

Answer 2

Solid ${->[Sublimation]}$ Vapour This process occurs in two steps, Step $1$ : Solid ${->[Fusion]}$ Liquid Step $2$ : Liquid ${->[Vaporisation]}$ Vapour Thus, Enthalpy of sublimation = Enthalpy of fusion + Enthalpy of vaporisation.