Which enthalpy changes can be calculated using only bond enthalpy data?

I.     ${{\text{N}}_{\text{2}}}{\text{(g)}} + {\text{3}}{{\text{H}}_{\text{2}}}{\text{(g)}} \to {\text{2N}}{{\text{H}}_{\text{3}}}{\text{(g)}}$

II.     ${{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{OH(l)}} + {\text{3}}{{\text{O}}_{\text{2}}}{\text{(g)}} \to {\text{2C}}{{\text{O}}_{\text{2}}}{\text{(g)}} + {\text{3}}{{\text{H}}_{\text{2}}}{\text{O(g)}}$

III.     ${\text{C}}{{\text{H}}_{\text{4}}}{\text{(g)}} + {\text{C}}{{\text{l}}_{\text{2}}}{\text{(g)}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{Cl(g)}} + {\text{HCl(g)}}$

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

B

It should have been clear to candidates that liquid ethanol would require more than bond enthalpy data provided they knew the definition of the latter. 52% gave the correct answer.