Chapter 13 Alcohols, Phenols, and Thiols 13.3 Physical Properties of Alcohols, Phenols, and Ethers

Boiling Points of Alcohols contain a strongly electronegative O in the OH groups form hydrogen bonds between alcohol molecules have higher boiling points than alkanes and ethers of similar mass

Boiling Points of Ethers have an O atom, but no H is attached cannot form hydrogen bonds between ether molecules have boiling points similar to alkanes of similar mass

Solubility of Alcohols and Ethers in Water Alcohols and ethers are more soluble in water than are alkanes because the oxygen atom hydrogen bonds with water. Alcohols with 1–4 C atoms are soluble, but alcohols with 5 or more C atoms are not.

Comparing Solubility and Boiling Points

Solubility of Phenol Phenol is soluble in water has a hydroxyl group that ionizes slightly (so is a weak acid) is corrosive and irritating to the skin + H2O + H3O+

Learning Check Which compound would have the higher boiling point, ethyl methyl ether or 1-propanol? Explain.

Solution Which compound would have the higher boiling point, ethyl methyl ether or 1-propanol? Explain. 1-propanol would have the higher boiling point because alcohol molecules can form hydrogen bonds, but ether molecules cannot.

Learning Check Which compound would be more soluble in water, ethanol or 2-pentanol? Explain.

Solution Which compound would be more soluble in water, ethanol or 2-pentanol? Explain. Ethanol. An alcohol with two carbons in its chain is more soluble than one with 5 carbons. The longer alkyl chain diminishes the effect of the –OH group.