Exams › JEE Main › Chemistry

For 2-fluoroethanol, which sequence correctly represents the increasing order of stability of its three principal conformations—eclipsed, anti, and gauche?

1. Eclipsed, anti, gauche
2. Anti, gauche, eclipsed
3. Eclipsed, gauche, anti
4. Gauche, eclipsed, anti

Correct answer: Eclipsed, anti, gauche

Solution

In 2-fluoroethanol the gauche conformer is stabilized by an intramolecular O-H...F hydrogen bond (and the gauche effect), making it the most stable; the eclipsed form is the least stable. Increasing stability: eclipsed < anti < gauche.

Related JEE Main Chemistry questions

• Lactic acid loses its optical activity when the hydroxyl group is replaced by hydrogen because
• Which is the most suitable technique for separating a mixture of sugars?
• Which statement correctly compares the staggered and eclipsed conformations of ethane?
• Which statement correctly describes a common feature shared by optical and geometrical isomerism?
• Which substituent lowers the reactivity of a benzene ring toward electrophilic substitution, yet still mainly directs a new group to the ortho and para positions?
• Among the following substances, which has the greatest affinity for a proton?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →