Methyl propane has a lower boiling point than butane, although both have the same molecular mass.

This is because the boiling point of a compound is influenced by its molecular structure and the strength of intermolecular forces. Methyl propane has a more compact and symmetrical structure compared to butane, which allows for stronger intermolecular forces such as London dispersion forces. These stronger forces require more energy to overcome, resulting in a higher boiling point for butane compared to methyl propane.

This statement is incorrect. Butane has a lower boiling point than methylpropane, despite having a higher molecular mass. The boiling point of a substance is primarily determined by its intermolecular forces, not its molecular mass. Butane has weaker intermolecular forces (van der Waals forces) than methylpropane due to its more elongated shape and fewer branching points, resulting in a lower boiling point.