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.

 

Answer

 

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)

DECOMPOSITION OF CALCIUM CARBONATE - Teachoo.jpg

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)

                Sunlight 

PHOTOCHEMICAL REACTION OF SILVER CHLORIDE - Teachoo.jpg

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

              Electricity   

ELECTROLYSIS OF WATER - Teachoo.jpg

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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo