I just finished a lab where I distilled a mixture of 2-methyl-2-butene and 2-methyl-1-butene in a dilute solution of sulfuric acid. The boiling points of the compounds respectively are 38.57C and 31.6C. The bp range ended up being a constant 32C. How is this possible? Shouldn't it be higher than either of the alkene bps? What could cause the boiling point of a solution to decrease?