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InterviewSolution
| 1. |
when calcium oxide reacts with water why hydrogen gas is not formed?(even though heat is released) |
| Answer» The formation of slaked lime (calcium hydroxide, Ca(OH)2) when\xa0water\xa0is added to lime (CaO) is exothermic.\xa0CaO(s) +\xa0H2O\xa0(l) → Ca(OH)2(s) This\xa0reaction occurs\xa0when\xa0water\xa0is added to dry portland cement to make concrete, and heat evolution of energy as heat is evident because the mixture becomes warm.Calcium\xa0is a silvery-white metal; it is relatively soft, but much harder than sodium metal. Calcium is a member of the\xa0alkaline-earth metals\xa0(Group II on the periodic table); these metals react vigorously with water, although not as violently as the Group I metals such as sodium or potassium:Ca(s) + 2H2O(l) ——> Ca(OH)2(aq) + H2(g) | |