In the chair conformation of cyclohexane, how are the axial hydrogens oriented compared to the equatorial hydrogens?

In the chair conformation of cyclohexane, the axial hydrogens are positioned perpendicular to the plane of the ring, extending either directly up or down. This orientation allows them to alternate in direction along the vertical axis of the cyclohexane molecule. In contrast, the equatorial hydrogens are oriented outward from the ring, away from the center, at an angle relative to the horizontal plane. This arrangement minimizes steric strain and interactions between substituents when the most stable conformation is adopted.

The key feature of the axial and equatorial positioning is that axial hydrogens create a more crowded environment, which can lead to steric interactions with neighboring substituents, known as 1,3-diaxial interactions. Meanwhile, the equatorial hydrogens, being angled outward, have more space available and less steric hindrance.

Thus, the correct characterization is that axial hydrogens point up or down, while the equatorial hydrogens are angled outward relative to the plane of the cyclohexane.