If the enthalpy change for hydrogenation of ethylene is -132 kJ/mole and the enthalpy of formation of 1, 3-butadiene (g) and butane (g) are 115 kJ/mol and -140 kJ/mole respectively then calculate the magnitude of resonance energy of 1, 3-butadiene (in kJ)?

Open in App

Solution

Enthalpy of hydrogenation of ethylene= $- 132 k J / m o l$
$∴$ Enthalpy related to hydrogenation of one $C = C$ is $- 132 k J / m o l$ .
$∴$ Calculated enthalpy of hydrogenation of $1, 3 - b u t a d i e n e = 2 \times (- 132) = - 264 k J / m o l$
Now, resonance energy of $1, 3 - b u t a d i e n e = Δ H_{e x p e c t e d} - Δ H_{a c t u a l}$
$= - 264 - (- 115 - 140)$
$= - 9$
$∴$ Resonance energy= $9 k J / m o l$

Suggest Corrections

Similar questions

Q. If enthalpy change for hydrogenation of ethylene is

- 132

kJ/mole and enthalpy of formation

1, 3

-butadiene (g) and butane(g) are

115

kJ and

- 140

kJ/mole respectively then calculate resonance energy of

1, 3

-butadiene (in kJ)?

Enthalpy of hydrogenation is the enthalpy change when one mole of unsaturated compound is converted to saturated compound. $Δ_{H} h y d r o g e n a t i o n$ helps to calculate resonance energy.

The standard enthalpy of combustion at $25^{\circ} C$ of hydrogen, cyclohexene and cyclohexane are -300, -3600 and -3770 KJ/mole respectively. Calculate the heat of hydrogenation of cyclohexene.

Q. The enthalpy of hydrogenation for