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प्रश्न
What is the action of following on phenol at low temperature?
- dil. HNO3
- conc. H2SO4
- Br2/CS2
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उत्तर
- Dilute HNO3: Phenol reacts with dilute nitric acid at low temperature to give a mixture of ortho- and para-nitrophenol.

- Conc. H2SO4: At room temperature (298 K), phenol reacts with concentrated sulphuric acid to form o-phenolsulphonic acid.

- Br2 in CS2: When a reaction is carried out in a solvent of lower polarity like CS2 a mixture of ortho- and para-bromophenol is formed.

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