Question

The statement given below is incorrect. write the correct statement

The heat energy supplied during a physical change is utilized to change the composition of the molecules of a substance.

Answer 1

Chemical change: It is a type of change in which there is a change in the chemical properties of the substance and a new substance is formed.

• It is a type of irreversible change.
• Irreversible change: It is a type of change that cannot be reversed.
• Heat will be released or absorbed in this type of reaction.
• For example, Magnesium($\mathrm{Mg}$) when reacted with Oxygen(${\mathrm{O}}_2$) results in the production of Magnesium oxide($\mathrm{MgO}$), and energy is released in the form of light.
• $\underset{\mathrm{Magnesium}}{2\mathrm{Mg}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Magnesium}\mathrm{Oxide}}{2\mathrm{MgO}\left(\mathrm{s}\right)}+\mathrm{light}$
• Heat energy provided during a chemical change will result in a change in the composition of reactants and the new product form will have a different composition with respect to reactants.
• Composition means the identity and number of the chemical elements which are helping in making a particular compound
• Whereas heat energy provided during a physical change will only result in a change in its physical properties like shape, size, color, and many more but not the composition.

Correct statement: The heat energy supplied during a chemical change is utilized to change the composition of the molecules of a substance.