Which compound has the smallest heat of hydrogenation?
A) 5-methyl-1,2-hexadiene
B) (E)-5-methyl-1,3-hexadiene
C) 5-methyl-1,4-hexadiene
D) 2-methyl-1,5-hexadiene
E) (E)-2-methyl-2,4-hexadiene

Question

Quizplus · Accepted Answer

The compound with the smallest heat of hydrogenation is the most stable diene. Conjugated dienes are more stable than isolated or cumulated dienes. (E)-2-methyl-2,4-hexadiene is a conjugated diene, making it more stable and thus having the smallest heat of hydrogenation.

Which Compound Has the Smallest Heat of Hydrogenation