Question

Alcohols are comapratively more soluble in water than hydrocarbons of comparable molecular masses. Explain this fact.

Answer 1

Water and alcohols both are polar in nature. When an alcohol, is dissolved in water, it forms hydrogen bonds with water by breaking the H-bonding already existing between the water molecules.

Hydrocarbons are non-polar in nature and do not form H-bonds with water molecules. Therefore, alcohols are readily soluble in water whereas hydrocarbons are not.

$\dots \dots \stackrel{{\delta }^{+}}{H}-\stackrel{{\delta }^{-}}{\underset{H^{{\delta }^{+}}}{\underset{|}{O}}}\dots \dots \stackrel{{\delta }^{+}}{H}-\stackrel{{\delta }^{-}}{\underset{H}{\underset{|}{O}}}\dots \dots \stackrel{{\delta }^{+}}{H}-\stackrel{{\delta }^{-}}{\underset{R}{\underset{|}{O}}}\dots \dots$
Hydrogen bonding among alcohol and water