Problem

As alcohol chains grow longer, their aqueous solubility drops dramatically—even though they're still alcohols with a hydroxyl group. The key insight is that solubility is a competition between two forces: the polar $\ce{-OH}$ group that loves water, and the nonpolar hydrocarbon chain that doesn't. With short chains, the hydroxyl group dominates and pulls the whole molecule into solution; but as the chain lengthens, the hydrophobic tail increasingly outweighs the hydrophilic head, making the molecule reluctant to dissolve. Think of it as the alcohol becoming progressively "more like an oil."

As alcohol chains grow longer, their aqueous solubility drops dramatically—even though they're still alcohols with a hydroxyl group. The key insight is that solubility is a competition between two forces: the polar $\ce{-OH}$ group that loves water, and the nonpolar hydrocarbon chain that doesn't. With short chains, the hydroxyl group dominates and pulls the whole molecule into solution; but as the chain lengthens, the hydrophobic tail increasingly outweighs the hydrophilic head, making the molecule reluctant to dissolve. Think of it as the alcohol becoming progressively "more like an oil."