Final answer:
The molecule with the greatest entropy among the choices provided (CH3CH3, CH4, CH3CH2Br, CH3CH2I, and CH3CH2Cl) is CH3CH2I due to its higher molecular mass, more complex structure, and the presence of the heavy iodine atom.
Step-by-step explanation:
When considering which molecule would have the greatest entropy, we need to consider factors like molecular size, complexity, and physical state. For the molecules CH3CH3, CH4, CH3CH2Br, CH3CH2I, and CH3CH2Cl, we should look for the molecule with the largest number of atoms, the most complex structure, and the presence of heavier atoms, as these properties can contribute to a greater number of microstates and thus higher entropy.
Comparing the given molecules:
- CH3CH3 (ethane) and CH4 (methane) are relatively small and simple.
- CH3CH2Br (ethyl bromide), CH3CH2I (ethyl iodide), and CH3CH2Cl (ethyl chloride) contain halogen atoms, which are larger and add complexity to the molecule.
Considering that iodine is larger than bromine, which in turn is larger than chlorine, CH3CH2I would have the greatest entropy due to its higher molecular mass, more complex structure, and potentially more microstates. Additionally, in comparison to CH3CH2Br and CH3CH2Cl, the presence of iodine in CH3CH2I adds to the overall size and complexity, resulting in a higher entropy.
Thus, among the choices provided, molecule CH3CH2I would have the greatest entropy.