explain difference between sublimation and thermal dissociation of ammonium chloride
Thermal dissociation is the breaking apart of a molecule's bonds due to the introduction of heat.
NH4Cl --> NH3 + HCl
Sublimation is the transition of a substance directly from the solid phase to the gas phase without passing through an intermediate liquid phase. Sublimation is an endothermic phase transition that occurs at temperatures and pressures below a substance's triple point in its phase diagram.