Ch 7Alcohols, Phenols and Ethers — Class 12 Chemistry, concept-first.

Replacing one or more hydrogen atoms in a hydrocarbon with a different atom or group of atoms is one of the most productive ideas in organic chemistry — it turns a fairly unreactive starting material…

Alcohols, phenols and ethers are the three families of oxygen-containing compounds taken up in this unit.

Alcohols (and, in the same way, phenols) are grouped as monohydric, dihydric, trihydric, or, more generally, polyhydric, according to whether the molecule carries one, two, three, or many groups.

Phenols are classified on exactly the same basis as alcohols in §7.1.1 — by how many hydroxyl groups are attached directly to the aromatic ring.

Ethers are classified by whether the two carbon groups attached to the ether oxygen are the same or different.

The everyday name of an alcohol is built by taking the common name of the alkyl group joined to the carbon and simply adding the word "alcohol" after it.

The functional-group oxygen in alcohols, phenols and ethers is always hybridised — the same hybridisation state as the oxygen in a water molecule.

With the structure, classification and nomenclature of alcohols, phenols and ethers already in place, attention now turns to how alcohols and phenols actually behave as compounds.

Alcohols can be built up from three broad starting points: alkenes, carbonyl compounds, and Grignard reagents.

Phenol was first isolated in the early nineteenth century from coal tar, where it was known as carbolic acid. Today it is produced synthetically on an industrial scale.

Alcohols and phenols are both built from two parts joined together — a hydrocarbon portion (alkyl or aryl) and a hydroxyl group, .

Alcohols and phenols both carry a hydroxyl group, so at first glance their chemistry looks similar. But where that –OH group sits changes everything: in an alcohol it hangs off an carbon, while in a p…

Among all alcohols, two stand out for their large-scale industrial and everyday use: methanol and ethanol.

Ethers are the third functional-group family built on the oxygen atom in this chapter, alongside alcohols and phenols.

Ethers can be built in two principal ways: by dehydrating an alcohol, or by the Williamson synthesis, which joins an alkoxide (or phenoxide) ion to an alkyl halide.

The C–O bonds on either side of the ether oxygen are individually polar, so an ether molecule as a whole carries a net dipole moment.

Of all the functional groups covered so far in this chapter, the ether linkage is the least reactive — which is exactly why ethers are so widely used as inert solvents.

- Classification: Alcohols (), phenols (), and ethers () are classified by the number of alkyl/aryl groups attached to the oxygen.

These are the final answers printed at the end of the NCERT chapter. The book gives answers for some intext questions only — every question below links to our complete worked solution.

Higher-order thinking problems from the NCERT Exemplar.

Questions from official CBSE sample papers.