Question

Give one example of change in the substance’s colour during a reaction.

Answer 1

Hint: As we know that a chemical change cannot always be visible to the naked eye but sometimes it occurs to change the colour of chemicals or solution when a chemical change takes place. So here we have to give an example of change in the substance’s colour during a reaction.

Complete answer:
Let us understand the concept of colour change after the chemical reaction is completed followed by its examples:-
-A chemical reaction is a process where the bonds within the reactant molecules or compounds are broken and new bonds are formed within the product in order to create a new material which has completely different properties.
-When two or more substances combine or react together, they create new substances which sometimes have different molecular structures compared to the original substances that mean they absorb as well as radiate light in different ways due to which there is color change.
-An example of change in the substance’s colour during a reaction is as follows:-
$2FeS{{O}_{4}}\left( s \right)\text{ }+\text{ }heat\text{ }\to \text{ }F{{e}_{2}}{{O}_{3}}\left( s \right)\text{ }+\text{ }S{{O}_{2}}\left( g \right)\text{ }+\text{ }S{{O}_{3}}\left( g \right)$
Here the colour of ferrous sulphate ($FeS{{O}_{4}}$) is green which turns into red-brown after the reaction due to the formation of ferric oxide ($F{{e}_{2}}{{O}_{3}}$).

Note:
-Remember that a colour change in mixing of 2 non-reactive chemicals can also be just mixing of colours because both compounds have their own shades and form a new colour after being mixed but not due to change in composition of the substance.