Question

Explain the types of reaction with reference to oxygen and hydrogen. Illustratre with examples.

Answer 1

There are three main types of chemical reactions with reference to oxygen and hydrogen: 

1. Combination Reaction
   When two atoms react to form a compound, it is known as a combination reaction.
   For example:  \[2 H_2 + O_2 \to 2 H_2 O\]
2. Decomposition Reaction
   When a compound breaks into simple molecular substances from which it is made up, it is known as a decomposition reaction.
   For example:  \[2 H_2 O \to 2 H_2 + O_2\]
   1. Oxidation and reduction reaction:
      Oxidation:
      1. The addition of oxygen to a substance is called oxidation.
      2. The removal of hydrogen to a substance is called oxidation.
   2. Reduction:
      1. The addition of hydrogen to a substance is called reduction.
      2. The removal of oxygen to a substance is called reduction.
         For example:  \[CuO + H_2 \to Cu + H_2 O\]

In the above reaction, copper oxide is changing to Cu. That is, oxygen is being removed from copper oxide. So, copper oxide is being reduced to copper.

In the above reaction, H₂ changes into H2O. That is, oxygen is added to hydrogen, which is then oxidized to water.