Question

Convert Phenol into o-phenol sulfonic acid.

Hint:

Remember: Low temperature favors kinetic control (ortho), while high temperature favors thermodynamic control (para).

Answer 1

Step 1: Understanding the Concept:
Sulfonation of phenol is temperature-dependent. The \(-OH\) group is ortho-para directing.
Step 3: Detailed Explanation:
When phenol is treated with concentrated sulfuric acid (\(H_2SO_4\)) at a lower temperature (\(288-293 \text{ K}\)), the major product is o-phenol sulfonic acid (2-hydroxybenzenesulfonic acid).
At high temperature (\(373 \text{ K}\)), the para-isomer becomes the major product.
Chemical Equation:
\[ C_6H_5OH + \text{conc. } H_2SO_4 \xrightarrow{288 \text{ K}} \text{o-}HOC_6H_4SO_3H \]
Step 4: Final Answer:
Phenol yields o-phenol sulfonic acid when reacted with conc. \(H_2SO_4\) at room temperature.