Question

Break down of glucose into simpler substances is an example of ___ .

Answer 1

A chemical change is a permanent change in which new substances are formed whose chemical and physical properties are completely different from that those of the original substance.

Characteristics of chemical change:

• change is permanent and cannot be reversed.
• one or more new substance is formed.
• composition of the original substance does not remain the same.
• the heat or light may be produced or consumed during the reaction.
• exchange of energy takes place during the reaction.

Example: When glucose is broken down into simpler molecules in presence of oxygen, carbon dioxide, water, and energy are formed. The following reaction takes place:

$\underset{\mathrm{glucose}}{{\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6\left(\mathrm{s}\right)}+\underset{\mathrm{oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

This reaction takes place during cellular respiration.

Thus, Break down of glucose into simpler substances is an example of chemical change.