question_answer

It is necessary to add gypsum in the final stages of preparation of cement. Explain why?

Answer:

                Gypsum \[(CaS{{O}_{4}}.2{{H}_{2}}O)\] is added in the final stages of preparation of cement since when \[{{H}_{2}}O\] is added to cement it slows down the process of setting of cement so that it gets sufficiently hardened thereby imparting greater strength to it.