Question

Define the following terms.
(a) Enthalpy of fusion.
(b) Enthalpy of atomization.

Answer 1

(a) Enthaply of fusion: The enthalpy change or amount of heat absorbed that accompanies the fusion of one mole of a solid at constant temperature and pressure is called enthalpy of fusion. It is denoted by $\left({\Delta }_{sus}H\right)$.
(b) Enthalpy of atomization: The enthalpy change or amount of heat absorbed accompanying the dissociation of the molecules in one mole of a gaseous substance into free gaseous atoms at constant temperature and pressure is called enthalpy of atomization. It is also called heat of dissociation and it is represented by ${\Delta }_{diss}$H and in general as, ${\Delta }_{auto}$H.