Which statement describes a heterogeneous catalyst?
it is in a different phase than the reactants.
it is in the same phase as the reactants.
it increases the activation energy of a reaction.
it lowers the reaction rate.

The correct answer is option :

'It is in a different phase than the reactants'.

Explanation:

Catalyst are those chemical substance which effect the speed of the reaction.

There are two types of catalyst :

Heterogeneous catalyst are the catalysis in which catalyst are present in different phase from the reactants and the products.

Homogeneous catalyst are the catalysis in which catalyst are present in same phase as that of the reactants and the products.

the correct answer is:

a. formation of precipitation