Chemistry · Aromatic hydrocarbons: Nomenclature, benzene - structure and aromaticity, mechanism of electrophilic substitution, halogenation, nitration
Assertion Rate of nitration is Reason Formation of intermediate is rate determin
Assertion Rate of nitration is \( C_{6} H_{6} \simeq C_{6} D_{6} \simeq \) \( \boldsymbol{C}_{\boldsymbol{6}} \boldsymbol{T}_{\boldsymbol{6}} \) Reason Formation of intermediate is rate determining step in nitration of benzene, not the breaking of \( \boldsymbol{C}-\boldsymbol{H} \) or \( C-D \) bond
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Assertion is incorrect but Reason is correct
Step-by-step solution
The rate of nitration of benzene is independent of the isotopic substitution (H, D, T) because the rate-determining step is the formation of the sigma complex (arenium ion) from the attack of the nitronium ion on the benzene ring. The breaking of the C-H bond occurs in a subsequent fast step and does not affect the rate. Therefore, the assertion that the rates are approximately equal is correct, and the reason correctly explains this fact.