Hydrogenation of vegetable oils in the presence of finely divided $Ni$ as a catalyst. The reaction is:

$A$ substance that increases the activity of a catalyst is known as ........

Identify the role of glycerol in the following reaction: $2 H_2O_{2(\ell)} \xrightarrow{\text{glycerol}} 2 H_2O_{(\ell)} + O_{2(g)}$

Which of the following catalysts is commonly used during the production of ammonia by the Haber process?

$A$ catalyst increases the rate of reaction because it

For the following Assertion and Reason,the correct option is
Assertion : For hydrogenation reactions,the catalytic activity increases from Group $5$ to Group $11$ metals with maximum activity shown by Group $7-9$ elements.
Reason : The reactants are most strongly adsorbed on Group $7-9$ elements.