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.

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

Assertion (A): Silver bromide decomposition is used in black and white photography. Reason (R): Light provides energy for this exothermic reaction.

2 g of silver chloride is taken in a china dish and the china dish is placed in sunlight for some time. What will be your observation in this case? Write the chemical reaction involved in the form of a balanced chemical equation. Identify the type of the chemical reaction.