Gypsum is CaSO4.2H2O. Gypsum is added in 2-3% of weight to cement along with CaO (lime) and clay. Gypsum is added in order to increase the setting time of cement. Slowing the setting time of cement makes it harden sufficiently. The correct answer is (ii).
Rate this question :
Describe the impoNCERT - Chemistry Part-II