Question

Controlled hydrogenation of ethyne gives which of the following compounds?
A. Ethane
B. Ethene
C. Methane
D. None of these

Answer 1

During the catalytic hydrogenation of ethyne, ethene is formed first which in the next step is further reduced to ethane.

Answer 2

Answer:

The correct answer is  option B.

Explanation:

Hydrogenation : Addition of hydrogen atom in an unsaturated hydrocarbon is known as hydrogenation. In controlled hydrogenation the controlled amount hydrogen is used along with specific catalyst and reagents.

$CH\equiv CH+H_2\overset{\text{Lindlar's catalyst}}\rightarrow CH_2=CH_2$

Lindlar's catalyst :Lead and calcium carbonate in lead acetate poisoned with small amount of quinoline.

Controlled hydrogenation of ethyne gives ethene.