Explain why low molecular mass alcohols are soluble in water?


Solubility of alcohols and phenols in water is due to their ability to form hydrogen bonds with water molecule. The hydrocarbon part methoxy methane (ie., R group) tends to prevent the formation of hydrogen bonds.

Alcohols with lower molar mass will have smaller hydrocarbon part and therefore tendency to form hydrogen bonding is more and they are more soluble in water.
                  CH3CH2OH>CH3CH2CH2OH
 (More soluble)     (Less soluble)