Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Based on the Newman projections for the conformers of butane:

Conformer Identification: S is anti (staggered, most stable), P is gauche (staggered), R is partially eclipsed, and Q is fully eclipsed (least stable).

Stability Order: The correct stability order is S > P > R > Q, which makes statement (A) correct.

Potential Energy Order: Since potential energy is inversely proportional to stability, the correct order is Q > R > P > S (rendering statement D incorrect).

Maximum Strain & Energy: Both Van der Waals strain and potential energy are maximum for the least stable, fully eclipsed conformer Q, not R (rendering statements B and C incorrect).

Therefore, the incorrect statements are B, C, and D.