Question

Or
(a) Quicklime reacts vigorsously with with water, releasing a large amount of heat
(b) On heating copper powder in air, the surface of copper powder in air, the surface of copper
powder turns black.​

Answer 1

Answer:

A)Quick lime reacts vigorously with water to produce slaked lime releasing a large amount of heat. So the reaction is highly exothermic.

B)This black substance formed on the surface is because of the process called surface oxidation. Upon heating, the copper metal melts gradually and turns black on the surface. This is because the copper powder present in the china dish reacts with the atmospheric oxygen and forms copper (II) oxide