4) Which one of the steps while burning a candie is not reversible?
Answers
Answer:
the step while burning a candle that is not reversible is the burning of the thread in candle
Step-by-step Explanation:
A reversible change is a physical change that can be undone.
A final substance can be converted back to the original substance without creating any new material.
An irreversible change is a permanent change that cannot be undone.
Melting of wax is a reversible process. Since upon cooling, it changes back to solid wax. Similarly, Solidification of melted wax can be reversed which is the melting of wax.
In case of burning a candle, carbon dioxide, water vapour and soot all go into the air thereby we cannot get back the original candle. Thus, it is an irreversible process. Similarly, Reduction of size of candle during burning cannot also be reversed. A chemical reaction takes place between wax and oxygen. A chemical energy in the form of heat and light is released. A chemical process can never be reversed.