Organic Chemistry> hydrogenation...

which of the following has smallest heat of hydrogenation per mole

A) 1-Butene B)trans-2-butene

C)cis-2-butene D)1,3-butadiene

ans is D)1,3-butadiene. plzz explain how do we decide that..??

Ranjita yadav , 13 Years ago

Grade 11

4 Answers

bhaveen kumar

because more stable the alkene,lesser the heat of hydrogenation per mole of double bond, 1,3-Butadiene has the most stable double bond due to conjugation...

Approved

Last Activity: 13 Years ago

SaHitya ChAmoli

Stability of alkene inversily propotional to heat of hydrogination.So trans_2_butene are most stable then its heat of hydrogination is least.

Last Activity: 9 Years ago

Akansha Singh

1,3 butadiene is most stable,since we know heat of hydrogenation is inversely proportional to stability.now competition is between trans 2 butene and the butadiene...1st of all butadiene is conjugated and will have resonance which is not present in trans butene..but we can ask that later has hyperconjugation..?yes it has, but we know reasonance is more stronger effect than hyperconjugation.

Last Activity: 8 Years ago

ankit singh

Which of the following has the smallest heat of hydrogenation per mole ? Solution : 1,3-Butadiene shows the smallest heat of hydrogenation due to its higher stability which is due to resonance. trans -2- Butene is more stable than cis-2- butene on the basis of heat of hydrogenation

Last Activity: 5 Years ago