Question

An element which changes the rate of a chemical reaction but does not
undergo any change in itself, is called
1)Electrolyte 2) Catalyst 3) Lubricant 4) Litmus

Answer 1

answer is 2)catalyst.
☆Catalyst increases the rate of reaction but does not undergo any chemical changes.
For example,
☆N2+3H2 gives us 2NH3 .The catalyst used in this reaction is Fe.

Answer 2

Catalyst alters the rate of reaction without undergoing any chemical change in that reaction.