Questions: Which of the following statements about the conformations of acyclic alkanes is true? Multiple Choice In the staggered conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon. Conformations are the same arrangements of atoms that cannot be interconverted by rotation about single bonds. In the eclipsed conformation, the C-H bonds on one carbon bisect the H-C-H bond angle on the adjacent carbon. Rotating the atoms on one carbon by 60° converts an eclipsed conformation into a staggered conformation, and vice versa.

Solution Steps

Let's analyze each statement to determine its correctness:

1. In the staggered conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon.

   • This statement is incorrect. In the staggered conformation, the C-H bonds on one carbon are positioned such that they are as far apart as possible from the C-H bonds on the adjacent carbon, minimizing torsional strain.

2. Conformations are the same arrangements of atoms that cannot be interconverted by rotation about single bonds.

   • This statement is incorrect. Conformations are different spatial arrangements of atoms that can be interconverted by rotation about single bonds.

3. In the eclipsed conformation, the C-H bonds on one carbon bisect the $\mathrm{H}-\mathrm{C}-\mathrm{H}$ bond angle on the adjacent carbon.

   • This statement is incorrect. In the eclipsed conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon, leading to torsional strain.

4. Rotating the atoms on one carbon by $60^{\circ}$ converts an eclipsed conformation into a staggered conformation, and vice versa.

   • This statement is correct. Rotating one carbon by $60^{\circ}$ will change an eclipsed conformation to a staggered conformation and vice versa.

Final Answer