Question

why do copper vessels develop a greenish layer when exposed to moist air ? ​

Answer 1

Explanation:

When a copper vessel is exposed to moist air for a long time it develops a green layer on its surface. Copper corrodes by oxidation in which it reacts with oxygen in the air to form copper oxide.

Copper oxide then combines with carbon dioxide to make copper carbonate, which gives it a green colour. This process is called corrosion of copper.

The green material is a mixture of copper hydroxide (Cu(OH)2) and copper carbonate (CuCO3). The following is the reaction:

$2Cu(s)+H{2} O(g)+CO2 + O2 \\ →Cu(OH)2 + CuCO3(s)$

Copper(II) carbonate is a blue-green compound.

Answer 2

Answer:

Copper metal when exposed to air turns green in colour due to corrosion. When copper vessel is exposed to air in rainy season, the metal reacts with gases and moisture and atmospheric gases to form a mixture of copper carbonate and copper hydroxide. This gives a green colour to the surface of copper metal.

Explanation: