Question

Why metal like potassium nd sodium react violently with cold water​

Answer 1

Answer:

Metals like sodium and potassium react violently with cold water. These reactions are exothermic. The reaction is so violent and exothermic that the hydrogen which is evolved immediately catches fire.

Answer 2

Answer:

Metals at the top of the reactivity series (Sodium, potassium) react readily (violently) with cold water forming hydroxides with the liberation of H2, the heat evolved is sufficient for the hydrogen to catch fire.