Enthalpy:Enthalpy is the total heat content of a system. It's used in thermodynamics to calculate the energy change in chemical reactions.
Mole:A mole is a unit of measurement in chemistry. It represents 6.02214076 ร 10^23 particles - atoms, molecules, ions etc., of the substance.
Phase Transition: Phase transition refers to the transformation from one state of matter (solid, liquid, gas) to another. Heat of fusion is involved during phase transitions between solid and liquid states.