Question

Define a decomposition reaction. How can we say that (I) electrolysis of water, and (II) blackening of silver bromide when exposed to sunlight, are decomposition reactions ? Mention the type of energy involved in each case.

The type of reactions in which (I) calcium oxide is formed, and (II) calcium hydroxide is formed are opposite reactions to each other. Justify this statement with the help of chemical equations.

State any two observations when an electric current is passed through acidulated water, in a container having each electrode covered by test tubes filled with water.

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