Question

Which of the following has least solubility?

• A. n-Butyl alcohol
• B. sec-Butyl alcohol
• C. tert-Butyl alcohol
• D. All have the same solubility

Answer 1

The correct option is A

n-Butyl alcohol

If the molecule is branched its (hydrophobic) surface exposed to water is less than in a linear molecule. Due to this hydrogen bonding with water molecules is more easy in branched compounds as compared to linear compounds. Therefore, lesser the surface area, higher will be the solubility of compounds.
Order of surface area:
t-Butyl alcohol $<$ sec-Butyl alcohol $<$ n-Butyl alcohol .
Therefore, the order of solubility:
t-Butyl alcohol $>$ sec-Butyl alcohol $>$ n-Butyl alcohol .