Question

Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.

Answer 1

(a) Thermal decomposition is a chemical reaction where a single substance breaks into two or more simple substances when heated.
2FeSO4(s) $\xrightarrow{Δ}$ FeO3(s) + SO2(g) + SO3(g)
(Ferrous sulphate) (Ferric oxide) (Sulphur Oxide) (Sulphur trioxide)

(b) Photo decomposition is a chemical reaction in which a substance is broken down into simple substances by exposure to light (photons)
2AgCl(s) $\xrightarrow{light}$ 2Ag(s) + Cl2(g)
(Silver chloride) (Silver) (Chlorine)

(c) Electrolytic decomposition may result when the electric current is passed through an aqueous solution of a compound.
2Al2O3(aq) $\xrightarrow{ Electricity}$ 4AI(s) + 3O2(g)
(Aluminium Oxide) (Aluminium) (Oxygen)