Enthalpy of Hydrogenation of one mole of benzene to cyclohexane is
(Resonance energy of benzene $= - 150.4 kJ / mol$ )
(enthalpy of Hydrogenation of cyclohexene $= - 119.5 kJ / mol$ )

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

$- 208.1 kJ / mol$

$- 358.1 kJ / mol$

$+ 150.4 kJ / mol$

$- 269.9 kJ / mol$

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The Hydrogenation of cyclohexene forms cyclohexane

$C_{6} H_{10} + H_{2} \to C_{6} H_{12}$

As the breaking of 1 C=C Bond and the formation of 2 C-H Bonds has a net release of 119.5 kJ/mol,

So, in the case of benzene, 3 C=C bonds is hydrogenated by

$3 \times 119.5 kJ / mol = 358.5 kJ / mol$

Since, benzene has resonance energy, the enthalpy change of hydrogenation is:

$358.5 kJ / mol - 150.4 kJ / mol = 208.1 kJ / mol$

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE