Isobutane is thermodynamically more stable than butane. Which has the lower boiling point? Is there any relationship between thermodynamic stability and boiling point? Would you expect such a relationship between thermodynamic stability and melting point?

Thermodynamic stability refers to how stable a compound is in terms of its energy. Compounds with lower energy are more thermodynamically stable. In this case, isobutane is more thermodynamically stable than butane.

The boiling point of a compound is the temperature at which it changes from a liquid to a gas. To determine which compound, isobutane or butane, has a lower boiling point, we need to consider their molecular structures. Butane: \(\mathrm{CH_3CH_2CH_2CH_3}\) Isobutane: \(\mathrm{(CH_3)_3CH}\) Isobutane has a more branched structure compared to the linear structure of butane. In general, branched hydrocarbons have lower boiling points compared to their linear isomers. This is because branched compounds have less surface area for intermolecular forces (such as van der Waals forces), resulting in weaker attractive forces between the molecules, which require less energy to overcome. Thus, isobutane has a lower boiling point than butane.

There is no direct relationship between thermodynamic stability and boiling point. Thermodynamic stability is determined by the internal molecular energy, while boiling point depends on the intermolecular forces between the molecules. Although isobutane is more thermodynamically stable than butane, it doesn't necessarily mean it will have a higher or lower boiling point.

Similar to boiling points, the melting point of a compound depends on the intermolecular forces between the molecules and not on its thermodynamic stability. Melting point is the temperature at which a compound changes its phase from a solid to a liquid, and this phase change also depends on the strength of the intermolecular forces that need to be overcome. Thus, there is no direct relationship between thermodynamic stability and melting point. In conclusion, isobutane is more thermodynamically stable than butane and has a lower boiling point. However, there is no direct relationship between thermodynamic stability and boiling or melting points, as they depend on different factors.