Question

State why the molar enthalpy of vaporization of a substance is larger than its molar enthalpy of fusion (at constant pressure)

Answer 1

The enthalpy of vaporization for a substance is significantly larger than the enthalpy of fusion because vapor pressure decreases and boiling point increases as vaporization occurs. temperature remains constant during vapourization but not during melting. to form a vapor, all intermolecular forces must be overcome