Q.Chlorobenzene is nitrated with a mixture of concentrated $\text{HNO}_3$ and $\text{H}_2\text{SO}_4$. State the major product(s) formed, and explain why chlorobenzene nitrates more slowly than benzene itself even though the product is still predominantly ortho/para-substituted.

Nitration proceeds by electrophilic attack of the nitronium ion, $\text{NO}_2^+$, generated from the $\text{HNO}_3/\text{H}_2\text{SO}_4$ mixture. Chlorine's lone pair can stabilise the arenium-ion intermediate by resonance donation only when the electrophile attacks ortho or para to it, so substitution occurs almost entirely at those positions, giving mainly a mixture of o- and p-nitrochlorobenzene (with negligible meta product). At the same time, chlorine's strong inductive electron-withdrawal lowers the overall electron density of the ring at every position, including ortho and para, making even this favoured intermediate less stabilised, and the reaction overall slower, than nitration of unsubstituted benzene under the same conditi …

State both outcomes together -- the product distribution (o/p-directing) and the rate comparison (slower than benzene) -- since they ar …

Concluding that because the ring is deactivated, no useful reaction/product forms at all -- deactivation only means the r …