Reaction Bonds Present Energy of Bonds Broken and Formed (kJ/mol)
C + O2 → CO2
O=O

2 C=O

499

739

N2 + O2 → 2NO
N≡N

O=O

2 N=O

946

499

607

S + O2 → SO2
O=O

2 S=O

242

522

2CO + O2 → 2CO2
2 C≡O

O=O

4 C=O

1074

499

739

Which reaction is endothermic?

(1 point)

A. C + O2 → CO2

B. 2CO + O2 → 2CO2

C. N2 + O2 → 2NO

D. S + O2 → SO2