Question

12. Based on the following data, what is the CI-CI bond energy? H2(g) + Cl2(g) ? HCI(g); ?.? =-92.31 klimol-rxn Bond H-H H-CI Bond Energy (kJ/mol) 435 428 a. 432 kJ/mol b. 236 kJ/mol c. -236 kJ/mol d. -421 kJ/mol e. 421 kJ/mol 12.

Answer 1

H₂ + Cl₂ ------------------------------> 2HCl , $\Delta$ H = -92.31kj/mol

let x be the bond energy of chlorine molecule.

$\Delta$Hrxn = bond energy of 2x HCl - ( bond energy of H₂ + bond energy of Cl₂)

  2 x -92.31 =  2x 428 - ( 435 +x )

-184.62 = 856- 435 - x

x = 605.62 kj/mol

bond dissociation energy of chlorine = 605.62 kj/mol