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Chapter 13 Alcohols, Phenols, and Thiols. 13.3 Physical Properties of Alcohols, Phenols, and Ethers. Boiling Points of Alcohols. Alcohols contain a strongly electronegative O in the OH groups form hydrogen bonds between alcohol molecules
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Chapter 13 Alcohols, Phenols, and Thiols 13.3Physical Properties of Alcohols,Phenols, and Ethers
Boiling Points of Alcohols 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 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.
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.