Look at Figure which shows three situations
(a) a burning candle
(b) an extinguished candle
(c) melting wax.
Which of these shows a reversible change and why?
Open in App
Solution
Option (a) a burning candle, and option (b) an extinguished candle show irreversible changes because:
When a candle is burned, the wick burns and is converted to fumes so the candle fire extinguishes after some time, due to the decrease in size of the wick.
Whereas option (c) melting wax shows a reversible change.
In this process, only the physical state of wax changes from solid form to liquid which can be reversed back on cooling.