Question

When calcium metal is added to water, the gas evolved does not catch fire but the same gas evolved on adding sodium metal to water catches fire. explain why ?

Answer 1

Because calcium metal is less reactive then sodium metal so, when the calcium metal is added in water the gas is involved such as oxygen and hydrogen in less amount so it does not catch fire but we added sodium in water than the oxygen and hydrogen in large amount so it catch fire.

Answer 2

Answer:

When Sodium reacts with water, the reaction is highly exothermic and amount of heat evolved is sufficient for hydrogen gas to catch fire. Hence, hydrogen evolved catches fire. In case of Calcium the heat evolved during the reaction is not sufficient for any hydrogen gas to catch fire.