The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder it exists 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.

Question

The gas we use in the kitchen is called liquified petroleum gas (LPG). In the cylinder it exists 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.

Philoid · Accepted Answer

Process A is a physical change because no new substance is formed. The LPG in cylinder is in liquid form because of high pressure. When it comes out from the cylinder, it turns into a gaseous form. Thus, it is a physical change.

Process B is a chemical change because burning of gas is a chemical change.