JIPMER2005ChemistryThermodynamics (C)
C _ (dia) + O ₂ CO ₂ ; H=-395.4 ~kJ / mole C _ ( gr ) + O ₂ CO ₂ ; H=-393.5 ~kJ / mole C _ ( gr ) C _ (dia) ; H= ?
Options
- A-3.8
- B-1.9
- C+3.8
- D+1.9
Correct answer
D. +1.9
Step-by-step solution
C ( dia )+ O ₂ CO ₂( H =-395.4 ~kJ / mole ) ...(1) C ( gr )+ O ₂ CO ₂( H =-393.5 ~kJ / mole ) ...(2) subtracting eq. (1) from (2), we have aligned & C ( gr ) C _ (dia) ; & aligned ( H & =+1.9 ~kJ / mole ) & [ H =-393.5-(-395.4) & .=+1.9 ~kJ ~mol ⁻¹ ] aligned aligned