The dominant intermolecular force that must be overcome in converting liquid CH3OH to a gas is hydrogen bonding.

Hydrogen bonding is a special type of dipole-dipole interaction that occurs when a hydrogen atom is bonded to a highly electronegative atom (such as oxygen, nitrogen, or fluorine) and is attracted to another electronegative atom in a neighboring molecule. In the case of CH3OH, the hydrogen atom is bonded to the oxygen atom, which is highly electronegative.

To understand why hydrogen bonding is the dominant force in converting liquid CH3OH to a gas, let's first discuss the other options:

a) Dipole-dipole interaction: Dipole-dipole interactions occur between polar molecules, where the positive end of one molecule is attracted to the negative end of another molecule. While CH3OH is a polar molecule due to the difference in electronegativity between carbon and oxygen, the strength of dipole-dipole interactions is weaker than hydrogen bonding.

b) Covalent bonds: Covalent bonds are the strong forces that hold atoms together within a molecule. In the process of converting liquid CH3OH to a gas, the covalent bonds within the molecule are not broken, as only intermolecular forces are involved.

c) London dispersion forces: London dispersion forces are the weakest intermolecular forces and occur between all molecules, polar or nonpolar. These forces arise from temporary fluctuations in electron distribution, resulting in the creation of temporary dipoles. However, London dispersion forces are generally weaker than dipole-dipole interactions and hydrogen bonding.

d) Hydrogen bonding: As mentioned earlier, CH3OH molecules can form hydrogen bonds due to the presence of a hydrogen atom bonded to an electronegative oxygen atom. The hydrogen bond is formed between the hydrogen atom of one CH3OH molecule and the oxygen atom of another CH3OH molecule. Hydrogen bonding is stronger than dipole-dipole interactions and London dispersion forces, making it the dominant force in converting liquid CH3OH to a gas.

In conclusion, the dominant intermolecular force that must be overcome in converting liquid CH3OH to a gas is hydrogen bonding. This is because hydrogen bonding is stronger than other intermolecular forces such as dipole-dipole interactions and London dispersion forces.