Question

The metal used as a catalyst in the hydrogenation of oils is:
A. sodium
B. nickel
C. mercury
D. manganese

Answer 1

Hint:Hydrogenation reaction of alkene is basically the reaction where the hydrogen gets added in the double bond of the alkene or alkyne in presence of metal catalyst. Metals act like catalysts in solid state. That is why this catalysis is known as heterogeneous catalyst.

Complete step by step answer:
When the reactant and product of a reaction are in a different phase than that of the catalyst is called heterogeneous catalysis reaction. In case of hydrogenation of oils, the phase of catalyst and reactant and product are liquid and solid respectively.
Among all the given options only nickel can bind with both hydrogen and alkene or alkyne molecules. Due to this reason nickel can facilitate the reaction rate by giving a proper orientation of reaction to them. At the same time using nickel as a catalyst reaction cost becomes lower and cheaper. Due to these reasons nickel is used as a catalyst in many reactions as a catalyst.

So the correct option is B.

Note:
The Heber process is used to prepare ammonia. In this reaction nitrogen and hydrogen gas is used and to catalyst the reaction solid iron is used. This mechanism is also exothermic. The reaction is shown below,
\[{{\text{N}}_{\text{2}}}{\text{(g) + 3}}{{\text{H}}_{\text{2}}}{\text{(g)}}\xrightarrow{{{\text{Fe}}}}{\text{2N}}{{\text{H}}_{\text{3}}}{\text{(g)}}\]
This reaction is also a heterogeneous catalysis reaction.