Alcohols have higher b.p. than alkanes, ethers, and halides of comparable MW due to intermolecular hydrogen bonding (O-H...O). B.p. increases with chain length. For isomeric alcohols: 1° > 2° > 3° (branching reduces surface area and H-bonding efficiency). Lower alcohols (C1-C3) are completely miscible with water; solubility decreases as the hydrophobic alkyl chain grows. Methanol and ethanol are miscible in all proportions. Butanol is partially miscible. Pentanol and above are practically insoluble. Phenol is moderately soluble in water (partial H-bonding) but fully soluble above 66°C.