The enthalpies of combustion of carbon and carbon monoxide are -393.5 and respectively. The enthalpy of formation of carbon monoxide per mole is
- (A)110.5 kJ
- (B)-110.5 kJ✓ Correct
- (C)-676.5 kJ
- (D)676.5 kJ
Answer: (B)
Solution
Write the two combustions: at and at . The formation of carbon monoxide, , is got by subtracting the second from the first, so by Hess's law .
JEE Main · 2004 · 24 Apr 2004 · Offline · Single correct option