Question

The two alternative chair conformations of cis-1-bromo-2-methylcyclohexane differ in their Gibbs free energy. Using the data for ΔG (Axial-Equatorial) for monosubstituted cyclohexanes at room temperature (25ºC): Axial → Equatorial Group ΔG° (kJ/mol) Group ΔG° (kJ/mol) -0.8 -5.9 -2.4 -7.3 -3.9 1,2-gauche 3.8 Calculate the absolute value of the difference in the Gibbs free energy between the alternative chair conformations. kJ/mol Which group in this compound is in axial position in the energetically preferred chair conformation? _______

Answer 1

Answer:

a.) 4.9kj/mol

b.) -Br group

Explanation:

first all of your question did not make mention of the groups in the table.

here it is:-

axial group     ΔG°(kj/mol)    group     ΔG°kj/mol

CN                   -O.8                NH₂          -5.9

Br                     -2.4                 CH₃           -7.3

OH                    -3.9            1,2-gauche      3.8

The 6 axial groups are bonded one on each carbon and also they are parallel and also alternate from up to bottom.

a.)

to get the absolute ΔG;

ΔG = -2.4-(-7.3)

= -2.4+7.3

= 4.9KJ/MOL

b.)

the axial group in this compound which is in the axial position in the energetically preferred chain conformation is the -Br group

Please check attachment for diagram