The boiling points of primary, secondary, and tertiary alcohols with the same molecular weight differ due to the differences in their intermolecular forces, specifically hydrogen bonding and van der Waals forces.Primary alcohols have the hydroxyl group -OH attached to a carbon atom that is bonded to only one other carbon atom. Secondary alcohols have the hydroxyl group attached to a carbon atom that is bonded to two other carbon atoms. Tertiary alcohols have the hydroxyl group attached to a carbon atom that is bonded to three other carbon atoms.Hydrogen bonding is a strong intermolecular force that occurs between the hydrogen atom of the hydroxyl group and the oxygen atom of another alcohol molecule. Primary alcohols have more opportunities for hydrogen bonding due to the presence of two hydrogen atoms on the carbon atom adjacent to the hydroxyl group. Secondary alcohols have only one hydrogen atom on the adjacent carbon atom, and tertiary alcohols have no hydrogen atoms on the adjacent carbon atom. As a result, primary alcohols generally have stronger hydrogen bonding than secondary and tertiary alcohols.Van der Waals forces, also known as London dispersion forces, are weak intermolecular forces that arise from the temporary fluctuations in electron distribution around the molecules. These forces increase with the surface area of the molecules. Tertiary alcohols have a more branched structure, which leads to a smaller surface area and weaker van der Waals forces compared to primary and secondary alcohols.Considering these factors, the boiling points of alcohols with the same molecular weight generally follow the order: primary > secondary > tertiary. This is because primary alcohols have stronger hydrogen bonding and potentially stronger van der Waals forces compared to secondary and tertiary alcohols. Secondary alcohols have a higher boiling point than tertiary alcohols due to stronger hydrogen bonding, even though their van der Waals forces might be similar.