Question

What do you observe when a piece of paper is burnt?

Answer 1

Hint: Paper is made up of pulp obtained from trees and burning of paper results in the chemical change. When a piece of paper is burnt it refers to the combustion reaction. In a combustion reaction carbon compounds react with oxygen and hydrogen in air and produce carbon dioxide and water vapor.

Complete answer:
Paper is made from the pulp of trees. The pulp can be obtained from mainly fast-growing trees. And can also be obtained from the pulp of the trees of cotton, bamboo, and jute.
Most of the pulp obtained from the trees contains organic atoms such as oxygen, carbon and hydrogen atoms.
Thus, mostly paper consists of cellulose, hemi-cellulose and lignin. Cellulose is a polysaccharide. It belongs to the family of carbohydrates; it contains mainly carbon.
Thus, carbon related compounds when burned with oxygen and hydrogen gas in the atmosphere, results in the formation of carbon dioxide and water vapor. The ash will be left there and it is lighter than paper and can be easily destroyed. This is the chemical change observed during the burning of a piece of paper.

Note:
As most of the plants and trees contain cellulose, thus the pulp for the manufacturing of paper can be made from trees. Cellulose will be present mostly in all parts of the plants and trees. The cellulose fibers also have the high strength and durability which makes it useful to prepare paper.