AIIMS2001ChemistryThermodynamics (C)
Given that C + O ₂ CO ₂ ; H^ =-a ~kJ . 2 CO + O ₂ 2 CO ₂ ; H^ =-b ~kJ The heat of formation of CO is
Options
- Ab-2 a
- B2 a-b 2
- Cb-2 a 2
- D2 a-b
Correct answer
C. b-2 a 2
Step-by-step solution
aligned & : C + O ₂ CO ₂ ; H^ =-a ~kJ & 2 CO + O ₂ 2 CO ₂ ; H^ =-b ~kJ aligned Formation of CO can be written as : C + 1 2 O ₂ CO ; H^ =? Adding equation: C + O ₂ CO ₂ ; H^ =-a ~kJ CO ₂ CO + 1 2 O ₂ ; H^ = b 2 ~kJ We get H_f^ ( CO )= b 2 -a= b-2 a 2