Manipal MET2015ChemistryThermodynamics (C)
The enthalpy of combustion of carbon and carbon monoxide are -393.5 and -283 ~kJ / mol respectively. The enthalpy of formation of carbon monoxide per mole is
Options
- A110.5 kJ
- B676.5 kJ
- C-676.5 ~kJ
- D-110.5 ~kJ
Correct answer
D. -110.5 ~kJ
Step-by-step solution
aligned & I: C ( ~s )+ O ₂(g) CO ₂ ; H=-393.5 ~kJ / mol & II: CO ( ~g )+ 1 2 O ₂(g) CO ₂(g) ; & H=-283.0 ~kJ / mol aligned On substracting II from I III: C ( s )+ 1 2 O ₂( ~g ) CO ( g ) ; H=-110.5 ~kJ / mol This equation III also represents formation of 1 mole of CO and thus enthalpy of formation of CO (g) is -110.5 ~kJ / mol