Final answer:
Trans-1,2-dibromocyclohexane is more stable than cis-1,2-dibromocyclohexane due to less steric hindrance since the bromine atoms are positioned on opposite sides of the cyclohexane ring, reducing repulsion and molecular strain.
Step-by-step explanation:
The question of which is more stable between cis-1,2-dibromocyclohexane and trans-1,2-dibromocyclohexane can be answered by considering the steric interactions in the cyclohexane ring. In general, the trans isomer tends to be more stable than the cis isomer due to less steric hindrance. In the trans isomer, the two bromine atoms are on opposite sides of the ring, which decreases repulsion and strain. On the other hand, in the cis isomer, the two bromine atoms are on the same side, causing greater steric interactions and strain within the molecule.
This concept is true for several types of cycloalkanes, such as in the case of cis-trans isomerism. In cycloalkanes, cis and trans configurations are types of diastereomers because the rigid cyclic structure prevents the free rotation around carbon-carbon bonds. This intrinsic property is what differentiates their stability, boiling points and other physical properties.