Chemistry - STEREO ISOMERISM Question with Solution | TestHub

The chair is the most stable conformation of cyclohexane, and within the chair the substituent prefers the equatorial position. (III) is the chair with $\mathrm{C}{\mathrm{H}}_3$ equatorial - the most stable. (IV) is a chair but $\mathrm{C}{\mathrm{H}}_3$ is axial (two 1,3-diaxial gauche interactions); (I) and (II) are boat/twist-boat forms with torsional and flagpole strain.