The heat of dissociation of benzene in isolated gaseous atoms is 5335 kJ/mol . The bond enthalpies C-C, C = C and C - H bonds are 347.3, 615 and 416.2 kJ respectively. Magnitude of resonance energy of benzene is

Options

A. 1.51 KJ
B. 15.1 KJ
C. 151 KJ
D. 1511 KJ

Answer

C

Explanation

`Delta H_("Calculated")=Sigma (B.E.)_(R )-Sigma (B.E.)_(P)`
`Delta H_("Cal")=[3xx(B.E.)_(C=C)+6xx(B.E.)_(C-H)+3xx(B.E.)_(C-C)]-0`
`Delta H_("Cal")=[3xx(615)+6xx(416.2)+3xx(347.33)]`
`Delta H_("Calculated")=5384.1 KJ mol^(-1)`
Resonance energy `=Delta H_("Observed")-Delta H_("Calculated")`
`=5535-5384.1`
Resonance energy `~= 151 KJ`