The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder it exist as a liquid. When it comes out from the cylinder it becomes a gas (Change – A) then it burns (Change – B). The following statements pertain to these changes. Choose the correct one.
(i) Process – A is a chemical change.
(ii) Process – B is a chemical change.
(iii) Both processes A and B are chemical changes.
(iv) None of these processes is a chemical change
NCERT Solutions for Class 7th Science Chapter 6 Physical and Chemical Changes Page 66 Exercise Question 11



Process-a is a physical change as there is change of state whereas process-b is about combustion which is chemical change therefore answer is option (ii)