Question

Catalytic hydrogenation of ethene produces________________
A. Ethane
B. Acetylene
C. Methane
D. Ethyne

Answer 1

Hint: The addition of di-hydrogen in unsaturated hydrocarbons such as alkene, alkynes, etc. in the presence of a catalyst is known as catalytic hydrogenation. The catalyst used is Raney nickel, platinum, or palladium at room temperature.

Complete step by step answer:
The addition of di-hydrogen and alkene in the presence of Raney nickel, platinum, or palladium at room temperature or in the presence of ordinary nickel at 523K- 573K to form alkane is known as Sabatier and senderens reduction. The catalytic dehydrogenation of ethene is given as:

$C{H_2} = C{H_2} + {H_2}\xrightarrow[{Or{\text{ }}Pt{\text{ }}or{\text{ }}Pd}]{{Raney{\text{ }}N}}C{H_3} - C{H_3}$

As we see the catalytic hydrogenation of ethene produces ethane. Thus the correct answer is option A.

The catalytic hydrogenation of ethene is an example of a heterogeneous catalysis process. The mechanism of the above reaction involves the following steps.
Step 1: This step involves adsorption of the ethene molecules on the surface of the catalyst. After adsorption, bond breaking and bond formation takes place that involves breaking of pi bonds and new bonds between carbon and catalyst surface.
Step 2: The hydrogen molecules are also adsorbed and it involves breaking of hydrogen-hydrogen bonds and formation of new bonds between hydrogen and catalyst surfaces.
Step 3: As the bond between hydrogen and catalyst surface breaks, the hydrogen atom formed gets attached to the ethene molecule to form ethane.

So, the correct answer is Option A .

Note: Since the hydrogenation process increases the chemical stability of the products, they are used in manufacture of commercial goods and in the food industry to form spreads, margarine. Also, hydrogenation is used to liquefy coal so as to use it as fuel.