Heat of dissociation of benzene to elements is 5535 kJ mol -1. The bond enthalpies of C - C , C = C and C - H are 347.3 615.0 and 416.2 kJ respectively. Resonance energy of benzene is

Question

Heat of dissociation of benzene to elements is 5535 kJ mol -1. The bond enthalpies of C - C , C = C and C - H are 347.3 615.0 and 416.2 kJ respectively. Resonance energy of benzene is (A) 1.51 kJ (B) 15.1 kJ (C) 151 kJ (D) 1511 kJ

Tardigrade Admin · Accepted Answer

Calculated value of heat of dissociation

= 3 (C - C) + 3 (C = C) + 6 (C - H)

= 3 \times 347.3 + 3 \times 615.0 + 6 \times 416.2

= 1041.9 + 1845 + 2497.2 = 5384.1 k J

Resonance energy = experimental value- calculated value

= 5535.0 - 5384.1 = 150.9 \approx 151 k J

Q. Heat of dissociation of benzene to elements is $5535 k J m o l^{- 1}$ . The bond enthalpies of $C - C, C = C$ and $C - H$ are $347.3 615.0$ and $416.2 k J$ respectively. Resonance energy of benzene is

$1.51 k J$

$15.1 k J$

$151 k J$

$1511 k J$

Calculated value of heat of dissociation

$= 3 (C - C) + 3 (C = C) + 6 (C - H)$

$= 3 \times 347.3 + 3 \times 615.0 + 6 \times 416.2$

$= 1041.9 + 1845 + 2497.2 = 5384.1 k J$

Resonance energy = experimental value- calculated value

$= 5535.0 - 5384.1 = 150.9 \approx 151 k J$

Q. Heat of dissociation of benzene to elements is 5535kJmol−1. The bond enthalpies of C−C,C=C and C−H are 347.3615.0 and 416.2kJ respectively. Resonance energy of benzene is

1.51kJ

15.1kJ

151kJ

1511kJ