Which one of the following changes when a catalyst is used in a reaction?

The process in which one of the products acts as a catalyst is known as:

Which of the following nanoparticle catalysts is used in photocatalysis?

The decomposition of hydrogen peroxide can be slowed down by adding a small amount of acetanilide. Here,acetanilide acts as a/an ...... .

Fill in the blanks:
$1.$ $TiCl_4$ with $Al(CH_3)_3$ is called ............ catalyst.
$2.$ In the Haber process,ammonia is produced from a mixture of ............ .

In a chemical reaction,a catalyst . . . . .