For the reaction below, which of the alkynes listed would be expected to produce the product under the conditions shown?
A) I
B) II
C) III
D) IV
E) V

Question

For the reaction below, which of the alkynes listed would be expected to produce the product under the conditions shown?  
A) I 
B) II 
C) III 
D) IV 
E) V

Quizplus · Accepted Answer

The reaction shown is a hydrogenation reaction, in which an alkyne is converted to an alkane by addition of hydrogen (H2) in the presence of a catalyst (e.g. palladium on carbon). The product of the reaction is an alkane with the same number of carbons as the starting alkyne.
Among the options given, only III is an alkyne with three carbons (propyne), which would produce propane upon hydrogenation. The other options would produce products with different numbers of carbons or with different functional groups, and are therefore not expected to give the product under the conditions shown.

For the Reaction Below, Which of the Alkynes Listed Would