(i) Determine the percentage of the twist-boat conformers present in a sample of deuterated cyclohexane at room temperature if the free energy of the most stable chair conformer of deuterated cyclohexane is 23.6 kJ/mol lower than that of the twist-boat conformer.
(ii) Does your answer agree with the statement that says there is no more than one twist-boat conformer for every 10,000 chair conformers?

Consider the pair of conformations shown below. 

Determine the energy difference between the two conformations by comparing the Newman projections along the specified bonds. 

The compound, cis-1,3-dimethylcyclohexane, has two different chair conformers. Calculate the energy difference between its two conformers.

The following compound has two different chair conformers. Calculate the energy difference between the two conformers.
trans-1,3-dibromocyclohexane

The compound trans-1,2-diethylcyclohexane has two chair conformers. What is the energy difference between the conformers in kJ/mol?