Which of the following compounds is the most soluble in water?

Hint: Look for functional groups that will form H-bonds with water.

CH3CH2CH2CH2CH3

OHCH3CH2OCH2CH2CH3

CH3CH2CH2CH2CH2OH

OHCH2CH2CH2CH2CH2OH

OHCH2CH2CH2CH2CH2OH is the most soluble in water.

Explanation:

This molecule has - OH groups at both ends. The - OH will be able to interact positively without water molecules by forming hydrogen bonds with the H ends of water molecules. This is because the - OH 's are polar making the molecule also generally polar - which would otherwise be nonpolar without them. Water being a polar solvent it dissolves polar substances.