What happens when

(Write a chemical equation in each case)

(a) ethanol is burnt in the air?

(b) ethanol is heated with excess conc. H₂SO₄ at 443 K?

(c) a piece of sodium is dropped into ethanol?

(a) Ethanol, when burnt in air, undergoes complete oxidation and produces carbon dioxide and water.

C₂H₅OH + 3O₂→ 2CO₂ + 3H₂O +heat and light

(b) Concentrated H₂SO₄ is a good dehydrating agent. When ethanol is heated with excess conc. H₂SO₄, one water molecule is removed from it to form ethene (C₂H₄).

(c) When sodium is dropped into ethanol, the solution colour changes to pink from colourless. This happens due to formation of sodium ethoxide.

The reaction is given below:

2C₂H₅OH + 2Na ⇒ 2C₂H₅0Na + H₂