Q

# the nitration of benezene using mixed conc. H2SO4 and HNO3 If a large amount of KHSO4 is added to the mixture, the rate of nitration will be

the nitration of benezene using mixed conc. H2SO4 and HNO3 If a large amount of KHSO4 is added to the mixture, the rate of nitration will be
Nitrobenzene is formed in the nitration process of benzene using concentrated $H_2SO_4$ and $HNO_3$. The reaction is given by;
$HNO_3+H_2SO_4\rightleftharpoons NO_2^++HSO_4^- +H_2O$
If a large amount of $KHSO_4$ is added to the mixture, more $HSO_4^-$ ion furnishes and rate of electrophilic aromatic reaction slow down i.e concentration of electrophile is decreased.
Hence addition of a large amount of $KHSO_4$  to the mixture tends to slow down the rate of nitration.