Heats of hydrogenation of three alkenes are as follows:
2-methyl-1-butene (-119 kJ mol-1)
3-methyl-1-butene (-127 kJ mol-1)
2-methyl-2-butene (-113 kJ mol-1)
(a) Write the structure of each alkene and classify it as to whether its doubly bonded atoms are monosubstituted, disubstituted, trisubstituted, or tetrasubstituted.
(b) Write the tructure of the product formed when each alkene is hydrogenated.
(c) Can heats of hydrogenation be used to relate the relative stabilities of these three alkenes?
(d) If so, what is the predicted order of stability? If not, why not?
(e) What other alkene isomers are possible for these alkenes? Write their structures.
(f) What are the relative stabilities among just these isomers?