Question

2) Write one equation each for decomposition reactions in which energy is supplied in the form of heat, light an electercity​

Answer 1

Answer:

Decomposititon reaction requiring heat is known as thermal decomposition.

CaCO3---CaO + CO2

Decomposition reaction requiring light is known as photo chemical decomposition reaction, 2AgCl------

-2Ag + Cl2

Answer 2

When a single reactant break down into two or more products. Such type of reaction is known as Decomposition reaction.

Decomposition reaction is of three types.

• Thermal decomposition reaction
• Photo decomposition reaction
• Electric decomposition reaction

Calcium carbonate on heating decomposes into Calcium oxide and carbon-dioxide.

The following reaction will takes place-

$\sf{CaCO_3\:\xrightarrow{\text{Heat}}\:CaO\:+\:CO_2}$

The above reaction is an example of Thermal Decomposition Reaction.

Silver chloride on exposure to sunlight decomposes into silver and chlorine gas.

The following reaction will takes place-

$\sf{2AgCl \xrightarrow{Sunlight}2Ag+Cl_2}$

Silver chloride is white in colour but after decomposition silver becomes grey in colour. This reaction is used in black and white photography.

The above reaction is an example of Photo Decomposition Reaction.

When electric current is passed through water, it decomposes water $\sf{(H_2O)}$ into oxygen $\sf{(O_2)}$ and Hydrogen gas $\sf{(H_2).}$

The following reaction will takes place-

$\sf{2H_2O\:\xrightarrow{\text{electricity}}\:2H_2\:+\:O_2}$

The above reaction is Electric Decomposition Reaction.