A statement of Assertion followed by a statement of Reason is given. Choose the correct answer out of the following options. Assertion: The Eclipsed and the Staggered conformations of Ethane continuously flip from one form to the other. Reason: The torsional barrier between the Conformers of Ethane has a high value of about 50‌kJ‌/‌mol and this restricts free rotation around C−C bond.
Let's analyze both the assertion and the reason provided: Assertion: The eclipsed and the staggered conformations of ethane continuously flip from one form to the other. Reason: The torsional barrier between the conformers of ethane has a high value of about 50‌kJ∕mol and this restricts free rotation around C−C bond. To determine the correctness of each statement, we need to understand the conformations and the torsional barrier of ethane in-depth: 1. Ethane can easily interconvert between its staggered and eclipsed conformations due to rotation around the carbon-carbon single bond. This rotation happens continuously, as the energy barrier to this rotation is relatively low. 2. The torsional barrier, which is the energy required to rotate from one staggered conformation through the eclipsed conformation to the next staggered conformation, is about 12.5‌kJ∕mol (not 50‌kJ∕mol ). This lower value indicates that the barrier is not significant enough to restrict free rotation. Based on this analysis: Assertion: Correct. The eclipsed and staggered conformations of ethane do indeed continuously flip from one form to the other. Reason: Incorrect. The torsional barrier is about 12.5‌kJ∕mol, not 50‌kJ∕mol, and it is low enough to allow free rotation around the C−C bond. Therefore, the correct answer is: Option D: Assertion is correct but Reason is incorrect statement.