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Problems related to arranging the given alcohols or phenols on the order of their acidic strength.
Description:
You can expect questions that give the structures of different alcohols and ask you to arrange them in ascending or descending order of acidic strength. Questions related to the effect of substituents on acidity are also asked. Some assertion and reasoning questions will also be asked for the same topic.
How to Approach:
For the acidity of alcohols and phenols remember these points:
- Phenols are more acidic than aliphatic alcohols.
- Alcohols are weaker acids than water
- Alcohols are weaker acids than carboxylic acids
- Substituents that stabilise the alkoxide/phenoxide anion increase acidity.
- Electron-withdrawing groups like, halogens (F, Cl),nitriles (CN), nitro groups ), increase acidity.
- Electron-donating groups like methyl groups decrease acidity
- For aliphatic alcohols, the substituents that are closest to the functional group have the strongest effect.
