How do the density and boiling point of ethers compare with those of alcohols?

Compared to alcohols, ethers generally exhibit lower density and lower boiling points.1

The difference in boiling points is primarily due to the presence of the hydroxyl group in alcohols, which allows for intermolecular hydrogen bonding. Because ethers lack this strongly polarized O—H bond, their molecules cannot engage in hydrogen bonding with one another, resulting in significantly lower boiling points than alcohols of similar molecular weight. For instance, diethyl ether has a boiling point of 35 °C, while 1-butanol—which has the same molecular formula—boils at 118 °C.21