Compound X is CaO(Calcium oxide). CaO is extensively used in the cement industry. On treatment with water, CaO produces Ca(OH)2 which is alkaline in nature and turns red litmus to blue colour.
Ca +H2O→ Ca(OH)2
Calcium oxide (CaO)
Calcium oxide, commonly known as lime, is a chemical compound with the formula CaO. Calcium oxide, also known as quicklime, is an alkaline substance that has been in use since the medieval age. It is believed that quicklime is one of the oldest chemicals known to the human race. It can also be referred to as burnt lime or lime.