Question

Methane, CH4, has a higher melting point than butane, C4H10

Answer 1

No. As the mass increases, the melting point increase, because in that trend, the molecules are changing from gas to liquid to solid.

Answer 2

To add to @Hoslos 's answer, this is because as the molecule grows in size, more London dispersion forces between molecules are possible, meaning individual molecules in a sample of the compound are held together more strongly. This means it takes more energy to break these INTERmolecular attractions apart (increasing the boiling point), and also helps give rise to the phase (i.e solid, liquid, or gas) of the compound at a given temperature.