Very Short Question and Answers - Types of Chemical Reactions

A chemical reaction involves the breaking and making of bonds between atoms to produce new substances, without changing the identity of the elements involved.

This is called a combination reaction.

Slaked lime (calcium hydroxide) is formed.

This is known as a decomposition reaction.

The green color of ferrous sulphate changes and emits a characteristic odor of burning sulphur.

Carbon dioxide (CO₂) is released along with calcium oxide.

White silver chloride turns grey as it decomposes into silver and chlorine.

Energy in the form of heat, light, or electricity is required.

The blue color of the copper sulphate solution fades, and the iron nails develop a reddish-brown coating of copper.

A double displacement reaction involves an exchange of ions between two reactants.

Barium sulfate (BaSO₄) precipitate forms.

Energy is absorbed during an endothermic reaction.

This is an example of a decomposition reaction.

Nitrogen dioxide (NO₂) and oxygen (O₂) gases are produced.

Color changes and the formation of gases or precipitates are common visual indicators.

Silver and bromine gas are formed upon light exposure.

The reaction is exothermic, releasing heat energy.

2AgCl(s) → 2Ag(s) + Cl₂(g).

The decomposition of calcium carbonate to form calcium oxide and carbon dioxide.

Copper metal is deposited on the iron nails.