Question

Upto how many times a catalyst can affect the rate of reaction

Answer 1

First of all catalyst don't affect anything in rate of reaction it only increase the speed of reaction and remain unchanged in chemically A catalyst is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. When the reaction has finished, you would have exactly the same mass of catalyst as you had at the beginning.

Some examples

Some common examples which you may need for other parts of your syllabus include:

reaction

catalyst

Decomposition of hydrogen peroxide

manganese(IV) oxide, MnO2

Nitration of benzene

concentrated sulphuric acid

Manufacture of ammonia by the Haber Process

iron

Conversion of SO2 into SO3

during the Contact Process to make sulphuric acid

vanadium(V) oxide, V2O5

Hydrogenation of a C=C double bond

nickel