Question

give three types of decomposition reaction

Answer 1

Photo decomposition is a chemical reaction in which a substance is broken down into simple substances by exposure to light (photons).

Thermal decomposition reaction (Thermolysis) ...

Electrolytic decomposition reaction (Electrolysis) ...

Photo decomposition reaction (Photolysis)

Answer 2

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Here is your answer,

Thermal decomposition reaction :

When lead nitrate is heated, it decomposes into lead oxide, nitrogen dioxide and oxygen.

2Pb(NO3)2 ⇨ 2PbO + 4NO2 + O2

Lead nitrate ⇨ Lead oxide + Nitrogen oxide + Oxygen

In above examples, compound is decomposed because of heating, so, these reactions are called THERMAL DECOMPOSITION REACTION.


Electrolytic Decomposition:
Reactions in which compounds decompose into simpler compounds because of passing of electricity, are known as ELECTROLYTIC DECOMPOSITION. This is also known as ELECTROLYSIS.

Example: When electricity is passed in water, it decomposes into hydrogen and oxygen.

2H2O ⇨ 2H2 + O2


Photolysis or Photo Decomposition Reaction:
Reactions in which a compound decomposes because of sunlight are known as PHOTOLYSIS or PHOTO DECOMPOSITION REACTION.

Example: When silver chloride is put in sunlight, it decomposes into silver metal and chlorine gas.

2AgCl ⇨ 2Ag + Cl2

Similarly, when silver bromide is put under sunlight, it decomposes into silver metal and bromine gas.

2AgBr ⇨ 2Ag + Br2

Photographic paper has coat of silver chloride, which turns into grey when exposed to sunlight. It happens because silver chloride is colourless while silver is a grey metal.
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