question_answer 14)

The gas we use in the kitchen is called Liquefied Petroleum Gas (LPG). In the cylinder, it exists as liquid. When it comes out of the cylinder, it becomes a gas (change A). Then, it burns (change B). The following statements pertain to these changes. Choose the correct one. (a) Process A is a chemical change (b) Process B is a chemical change (c) Both processes A and B are chemical changes (d) None of the above processes is a chemical change  

Answer:

(b) Process B is a chemical change. Process A is a physical change. The LPG in cylinder is in liquid form because of high pressure. When it comes from cylinder, it turns into gas. It is a physical change. Process B is a chemical change because burning of gas is a chemical change.