Use the bond enthalpies given to estimate the heat released when ethene, CH₂=CH₂,Reacts with HBr to give CH₃CH₂Br.
Bond enthalpies (kJ.mol^-1) : C-H,412; C-C,348; C=C,612; C-Br,276; Br-Br,193; H-Br,366.

Question

Quizplus · Accepted Answer

The reaction involves breaking one C=C bond (612 kJ/mol) and one H-Br bond (366 kJ/mol), and forming one C-C bond (348 kJ/mol), one C-H bond (412 kJ/mol), and one C-Br bond (276 kJ/mol). The heat released is calculated as: (612 + 366) - (348 + 412 + 276) = 58 kJ/mol.

Use the Bond Enthalpies Given to Estimate the Heat Released