(i) The reactants are ethanol and oxygen, and ethanol undergoes complete oxidation to produce carbon dioxide and water, with the generation of heat and light.

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

(ii) Ethanol when heated with a dehydrating agent like conc. H₂SO₄ loses a water molecule to produce ethene.

(iii) The reactants are ethanoic acid and sodium bicarbonate. They react to produce the sodium salt of ethanoic acid, along with the formation of carbon dioxide and water.