Isomers are molecules with the same elemental composition but a different atomic arrangement. Three isomers with the formula C₄H₈ are shown in the models below. The enthalpy of combustion (∆_cH°) of each isomer, determined using a calorimeter, is as follows: 

(a) Draw an energy level diagram relating the energy content of the three isomers to the energy content of the combustion products, CO₂(g) and H₂O(ℓ).

(b) Use the ∆_cH° data in part (a), along with the enthalpies of formation of CO₂(g) and H₂O(ℓ) from Appendix L, to calculate the enthalpy of formation for each of the isomers.

(c) Draw an energy level diagram that relates the enthalpies of formation of the three isomers to the energy of the elements in their standard states. 

(d) What is the enthalpy change for the conversion of cis-2-butene to trans-2-butene

Transcribed Image Text:

Compound AcH (kJ/mol butene) cis-2-butene -2709.8 trans-2-butene -2706.6 1-butene -2716.8