Question

The products of burning candle are:
A. ash and water vapor
B. $C{{O}_{2}}$ and water vapor
C. wax and water vapor
D. only melted wax

Answer 1

Burning of candle is defined as both physical as well as chemical change. This change can be explained on the basis that when we lighten up the candle then wax acts as a fuel which is defined as a chemical substance known by the name carbon.

Complete answer:
When we lightened up the candle then we noticed that the wax near the wick started melting and the liquid wax started evaporating due to the heat produced by flame. Here we can see the physical change that how solid converts into liquid then it converts into gas. On the other hand we can consider that burning is a chemical change process which involves an oxidation process which further produces heat and light.
When a candle is burnt in the presence of air then mass of the product is increased due to the atmospheric oxygen which combines with the carbon and hydrogen present in the candle wax during burning and produces water vapour and carbon dioxide. And this type of reaction is irreversible in nature i.e. once a product is formed then it can-not be regained into the starting product.

Hence from the above discussion we can conclude that option B is the correct answer.

Note:
Chemical change in the candle is irreversible in nature but the physical change is said to be of reversible nature as when we heat the wax it melts and converts into liquid state but when we stop heating then it again mold itself in solid state so we can say that physical change is reversible in nature.