Barrier To Rotation Practice Problems

Assume that the temperature is 298 K. Consider the following bond rotation and use the given table to answer the questions below:

(a) Which conformation is more stable? 

(b) Determine the ΔG° for the process. 

(c) Determine the equilibrium constant (K_eq).

(d) Provide the transition state for the process.

Even though free rotation is generally observed around most σ bonds, the C–N bond in an amide demonstrates restricted rotation, as depicted below. Which of the following factors primarily accounts for this behavior? 

(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?