What is a catalyst? Write any one reaction which is brought about by use of a catalyst.

Explanation

Catalyst: A substance which increases the rate of reaction without causing any disturbance is called a catalyst.
Vegetable oils are converted into vanaspati ghee by passing hydrogen in presence of nickel as catalyst.
`"Vegetable oil "+ H_(2) overset(Ni)to "vanaspati ghee"`
`H-underset(|)overset(H)overset(|)C-underset(|)overset(H)overset(|)C -underset(Pt//Ni)overset(H_(2))to -underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-`