6. Thermodynamics and Kinetics
Enthalpy
18PRACTICE PROBLEM
Compute the overall ∆Hº for the iodination of methane which proceeds through the following steps:
1. I2 + 2I•
∆Hº (per mol) = +149 kJ (+35.6 kcal)
2. CH4 + I• → •CH3 + HI
∆Hº (per mol) = +141 kJ (+33.7)
3. •CH3 + I2 → CH3I + I•
∆Hº (per mol) = −92 kJ (−22.0 kcal)
Compute the overall ∆Hº for the iodination of methane which proceeds through the following steps:
1. I2 + 2I•
∆Hº (per mol) = +149 kJ (+35.6 kcal)
2. CH4 + I• → •CH3 + HI
∆Hº (per mol) = +141 kJ (+33.7)
3. •CH3 + I2 → CH3I + I•
∆Hº (per mol) = −92 kJ (−22.0 kcal)