Question

What can be said appropriately regarding catalytic hydrogenation of an alkene?

• A. it occur in syn orientations.
• B. it occur in both syn and orientations.
• C. If some $D_2$ contaminate the $H_2$, addition of H-D may be observed.
• D. it can be affected using $LiAI{H}_4$ in most cases.

Answer 1

Answer: (A), (C)

it occur in syn orientations.
If some $D_2$ contaminate the $H_2$, addition of H-D may be observed.

a) Reaction occurs at the surface of metal, syn hydrogenation always takes place.

c) $D_2+H_2\to 2H-D.$ Hence, some $H-D$ addition may take place.

d) $LiAl{H}_4$ is not effective in catalytic hydrogenation of alkene.