Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants write one equation each for decomposition reaction where energy is supplied in the form of heat light and electricity.
The following are the reactions involving energy in the form of heat or light or electricity for breaking down the reactants in Decomposition reactions:
Heat - Decomposition of Calcium Carbonate (CaCO 3 )
On heating of Calcium Carbonate (limestone),
It decomposes into Calcium Oxide (Quick Lime) + Carbon Dioxide
CaCO 3 (s) → CaO(s) + CO 2 (g)
(Limestone) Heat (Quick lime)
Light - Silver Chloride turns grey in sunlight
It is because, the heat of sunlight decomposes silver chloride into silver and chlorine
2AgCl(s) → 2Ag(s) + Cl 2 (g)
Electricity - Electrolysis of water
The breaking down of H 2 O into H 2 and O 2 by passing electricity is known as electrolysis of water.
2H 2 O → 2H 2 + O 2