Chemical Reactions and Equations

Types of Chemical Reactions

Breaking and formation of new bonds between atoms to produce new substance is called chemical reaction.

On the basis of breaking and making of bonds between atoms and formation of new compounds Chemical

Reaction can be divided into following types:

• Combination Reaction
• Decomposition Reaction
• Displacement Reaction
• Double Displacement Reaction
• Oxidation Reaction

Combination Reaction:

Chemical reactions in which two or more substances react to form one compound are called Combination Reactions. Combination means to get combine.

Example: 1:

When quick lime reacts with water, water and quick lime go under combination reaction and give calcium hydroxide.

Calcium hydroxide (slaked lime) produced in this reaction because of combination reaction between quick lime and water. This calcium hydroxide (slaked lime) is used in white washing of walls.

Calcium hydroxide, which is formed in this combination reaction reacts very slowly with carbon dioxide present in air and forms calcium carbonate. This calcium carbonate gives shiny look to walls after two to three days of white washing.

Example: 2:

When coal is burnt in air, it goes under combination reaction with oxygen present in air and forms carbon dioxide.

Example: 3:

Hydrogen gas and oxygen gas go under combination reaction and produce water.

Example: 4:

When magnesium ribbon is burnt in air, it goes under combination reaction with oxygen present in air and forms magnesium oxide.