Chemistry
Rajat mixed a white coloured compound A with water. The compound A reacted vigorously with water to produce a compound B and large amount of heat. He used the compound B to white wash the walls.
After 3 days of whitewash, the walls became shiny
(a) Name the compound A
(b) Why the walls appear shiny ? Write the reactions involved.
(c) State the type of reaction occurred here.
Answer
(a) Calcium oxide [CaO]
(b) The walls appeared shiny on the 3rd day due to the reaction of calcium hydroxide with carbon dioxide present in the air to produce white-colored calcium carbonate.
CaO + H2O ⟶ Ca(OH)2 + heat
Ca(OH)2 (aq) + CO2 (g) ⟶ CaCO3 (s) + H2O (l)
(c) Precipitation reaction
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