By adding gypsum to cement : — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Cement is composed of calcium silicates and aluminates. When water is added, tri-calcium aluminate hydrates very rapidly, causing the cement to set too quickly (flash setting). Step 2: Gypsum (CaSO4 . 2H2O) is added to cement clinker during grinding. It reacts with tri-calcium aluminate to form an insoluble calcium sulfoaluminate compound, which retards the hydration reaction. Step 3: This reaction slows down the initial setting process, meaning the setting time of cement increases, which matches option (b).