[r3pnit]

 At room temperature 2 - methylbutane exist primarily as two alternating conformations of roation about the C2- C3 bond. About 90% of the molecules exist in the more favorable conformation and 10% in the less favorable one .

a) calculate the free energy chance (delta G) , more favorable conformation - less favorable conformation) between these conformation

b)draw a potential energy diagram for rotation about the C2- C3 bond in 2 methyl butane

C) Draw newman projection for all staggered and ecliped rotamers in (b) and idicate the two most favorable ones


edit: my teacher emailed me this if this helps:

To estimate the energy of the peaks in the energy diagram utilize the following formula. Every hydrogen overlapping a hydrogen costs 0.9 kCal/mol of energy. Every hydrogen overlapping a methyl costs 1.4 kCal/mol of energy. Every methyl overlapping a methyl costs 3.6 kCal/mol of energy. Your drawing does not need to be super precise. As long as the point gets across.
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[a student]

look at advanced organic chemistry, Francis A. Carey, part a, 4th edition, chapter 3, page 127.
I hope it helps