By applying Hess's Law to phase transitions, the enthalpy of sublimation () of a solid is mathematic — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Sublimation is the direct transition from solid to gas. Thermodynamically, this is equivalent to first melting the solid to a liquid (Fusion) and then boiling the liquid to a gas (Vaporization). Thus, $\Delta_{sub} H = \Delta_{fus} H + \Delta_{vap} H$.