Which of the following processes is involved in chemical reactions?

Question

Question

This question was previously asked in

RRB JE CBT I - (Held On: 30 May 2019 Shift 1)

Answer 1

The correct answer is Heating copper wire in the presence of air at high temperature

Key Points

Heating copper wire in the presence of air at high temperature is a chemical reaction because it involves a change in the chemical composition of the copper wire, forming copper oxide.
In contrast, melting of ice to give water is a physical change, not a chemical reaction, as it only involves a change in the state of matter.
Similarly, storing oxygen gas under pressure in a gas cylinder and liquefaction of air are physical processes and do not involve any chemical changes.

Additional Information

Chemical reactions involve the breaking and forming of chemical bonds, resulting in new substances with different properties from the reactants.
Physical changes, on the other hand, do not alter the chemical composition of the substance but may change its state or appearance.
Examples of chemical reactions include combustion, oxidation, and acid-base reactions.