Question

Which coloured entity can be changed to balance the chemical reaction?

• A. Entities in green
• B. Entities in red
• C. Entities in both red and green
• D. None of the colour

Answer 1

The correct option is A

Entities in green

The entities in green and red respectively are called coefficients and subscripts.

Subscripts of a chemical formula represent the number of atoms in the compound, changing these would result in the formation of a new compound. So these should not be changed while balancing the chemical reaction.

Example: Consider water $H_2{O}_1$ , subscript of hydrogen is 2 and of oxygen is 1. If subscript of oxygen is changed to 2 i.e. $H_2{O}_2$ will result in new compound hydrogen peroxide.

Coefficients represent the number of molecules involved in a chemical reaction. Changing these would not change the composition of the compound. So only these can be changed to balance the reaction.

Example: $H_{2}O$ represent 1 molecule of water.

$2H_{2}O$ represents 2 molecules of water.