Common name of Benzene-1, 2-diol is
Alcohols, Phenols & Ethers · Class 12 · JEE Main Previous Year Question
Common name of Benzene-1, 2-diol is
- a
quinol
- b
resorcinol
- c✓
catechol
- d
o-cresol
catechol
Step 1: Understand the compound
Benzene-1,2-diol is a benzene ring with two groups on adjacent (1,2-position = ortho) carbons.
Step 2: Recall common names of dihydroxybenzenes
The three dihydroxybenzene isomers have specific common names:
| IUPAC Name | Position | Common Name | |---|---|---| | Benzene-1,2-diol | ortho (1,2) | Catechol | | Benzene-1,3-diol | meta (1,3) | Resorcinol | | Benzene-1,4-diol | para (1,4) | Quinol (Hydroquinone) |
Step 3: Eliminate wrong options
- Quinol = benzene-1,4-diol (para isomer) → option (a) wrong
- Resorcinol = benzene-1,3-diol (meta isomer) → option (b) wrong
- o-Cresol = 2-methylphenol (has a methyl group, not a second OH) → option (d) wrong
Answer: Catechol = Benzene-1,2-diol ✓
Key Points to Remember:
- Catechol = ortho (1,2); Resorcinol = meta (1,3); Hydroquinone/Quinol = para (1,4)
- A simple mnemonic: C-R-Q = ortho-meta-para (alphabetical C before R before Q)
- o-Cresol has -CH3 + -OH, not two -OH groups.
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