Question 1 - MCQs from NCERT Exemplar - Chapter 1 Class 10 - Chemical Reactions and Equations

Which of the following is not a physical change?

(A) Boiling of water to give water vapour

(B) Melting of ice to give water

(C) Dissolution of salt in water

(D) Combustion of Liquefied Petroleum Gas (LPG)

Answer

A physical change is the one in which the chemical properties of a substance do not change . 

Let’s check all the options

• In the case of boiling of water and melting of ice, only the physical state of water changes . Therefore, these both are physical changes.
• In the case of melting of ice , only the physical state of water changes . Therefore, these both are physical changes.
• When we dissolve salt in water, salt simply fits into the voids/gaps between the water molecules and no chemical property is changed. Hence, it is also a physical change.
• However, during combustion of LPG, it reacts with oxygen to release CO ₂ gas. This is a chemical change

So, the correct option is (d)