water
The smallest and lightest alcohols methanol, ethanol, propanol are completely soluble in water in all proportions. In a solution, the hydroxyl groups of alcohol molecules and the water molecules form hydrogen bonds with each other, resulting in complete miscibility. However, as the length of the carbon chain increases, the solubility decreases. The solubility of 1-butanol is 7.4 g per 100 g of water, while that of 1-pentanol is 2.7 g per 100 g water, and 1-octanol is 0.06 g per 100 g water. The carbon chain portion of the larger alcohol molecule is nonpolar and leads to the decreased solubility of the overall compound.