Which one of the following is an example of chemical change ?

Which one of the following is an example of chemical change ?

Burning of paper
Magnetization of soft iron
Dissolution of cane sugar in water
Preparation of ice cubes from water
This question was previously asked in
UPSC CDS-1 – 2016
Burning of paper is an example of a chemical change.
– A chemical change involves a chemical reaction where one or more substances are transformed into different substances with different properties.
– Burning is a combustion reaction where paper reacts with oxygen, producing ash, carbon dioxide, water vapor, and other substances. This process forms new chemical compounds and is not easily reversible.
– Physical changes alter the form or appearance of a substance but not its chemical composition. Magnetization, dissolution, and phase changes (like freezing water) are physical changes, as the original substances retain their chemical identity and the process is often reversible.
Key indicators of a chemical change include changes in color, temperature, formation of gas or precipitate, and difficulty in reversing the process.