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प्रश्न
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. Why is it so?
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उत्तर
Sodium is more reactive than calcium. The reaction between sodium and water produces a large amount of heat, causing the evolved hydrogen to ignite. But in the reaction between calcium and water, no heat is produced; hence, the evolved hydrogen does not catch fire.
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