Question

What is reduction?

Answer 1

Hint: In general language reduction is to reduce, decrease the amount of anything. In terms of chemistry reduction means when the oxidation state of an element decreases.

Complete step by step answer:
In redox reaction oxidation and reduction takes place. In chemical reaction whenever an element gains electrons and its oxidation state decreases we can say that reduction has taken place. Sometimes the term is also used to refer to the element that accepts electrons, as the oxidation state of the element that gains the electron is lowered. The formation of non-metal ions from the corresponding element i.e. $\text{C}{\text{l}}_{\text{2}}\text{+2}{\text{e}}^{\text{-}}\to \text{2C}{\text{l}}^{\text{-}}$ is an example of reduction. Here we can see that the oxidation state of chlorine changes from 0 to -1 hence, we can say that reduction has taken place.
So, we can conclude that reduction means gaining of electrons or we can also say that when oxidation state of any element decreases.


Additional Information:
Reduction is a part of a redox reaction. It involves the half reaction in which a chemical species decreases its oxidation number, usually by gaining electrons.
This process is considered as the opposite of the oxidation process.
Reducing agents are elements or compounds that donates an electron to another species in a redox reaction.
Sometimes this terminology is also used with reduced gas. Reduced gas means a gas with low oxidation number.

Note: Some books write reduction as removal of oxygen or the addition of hydrogen. So, there are high chances that students may confuse between all these, but remember one thing all these definitions point towards the same meaning. We use term reduction when we are talking about a decrease in oxidation state.