4. A plait point is the point on the solubility curve, where the tie line reduces to a point. What is the number of plait point for a ternery system containing twopairs of partially miscible liquids?
6. Use of catalyst is a must in the ammonia manufacture, because the reaction is reversible as well as the heat of dissociation of N2 & H2 is high. The presence of promoter along with the catalyst helps in __________ of the catalyst.