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:
Phenol undergoes electrophilic substitution. The sulfonation of phenol is temperature-dependent.
Step 2: Detailed Explanation:
When phenol is treated with concentrated sulfuric acid (\(H_2SO_4\)) at room temperature or low temperature (around 288 K), the major product is ortho-phenol sulfonic acid.
At higher temperatures (373 K), the major product shifts to para-phenol sulfonic acid due to thermodynamic stability.
Reaction:
\[ C_6H_5OH + \text{conc. } H_2SO_4 \xrightarrow{288 K} \text{o-hydroxybenzene sulfonic acid} \]
Step 3: Final Answer:
Phenol is converted to o-phenol sulfonic acid by reacting it with conc. \(H_2SO_4\) at 288 K.