Which one of the following processes involves chemical reaction ?

Which one of the following processes involves chemical reaction ?

Evaporation of petrol
Dissolution of salt in water
Storing of oxygen gas under pressure in a gas cylinder
Burning of magnesium ribbon in air
This question was previously asked in
UPSC NDA-2 – 2023
Burning of magnesium ribbon in air involves a chemical reaction.
A chemical reaction involves the rearrangement of atoms and molecules to form new substances with different chemical properties. Evaporation, dissolution, and storing gas under pressure are physical processes where the substance’s chemical composition remains unchanged, only its state or distribution changes. Burning (combustion) is a chemical process where a substance reacts rapidly with oxygen, typically producing heat and light and forming new chemical compounds. When magnesium burns in air, it reacts with oxygen and nitrogen to form magnesium oxide and magnesium nitride, respectively.
Evaporation is a phase transition from liquid to gas. Dissolution is the process of dissolving a solute in a solvent to form a solution; the solute particles disperse but do not chemically change. Storing gas under pressure is a physical change affecting density and volume. Burning involves chemical transformation.
Exit mobile version