Nitrobenzene is made by the direct nitration of benzene by nitric acid in the presence of strong sulphuric acid solution: C6H6 + HNO3 C6H5NO2 + H2O
The actual nitrating agent is the nitronium ion, NO2+, and the sulphuric acid is needed to generate this from the nitric acid feed. Sulphuric acid, of strength 66% by weight and 90˚C is mixed with pure nitric acid at 25˚C to give a nitric acid strength in the mixture of 7.5% by weight and temperature of X˚C. The mixed acid is then passed through a heat exchanger to bring its final temperature to Y˚C and fed to the reactor. Liquid benzene at 25˚C is also fed to the reactor at a rate to give a 10% stoichiometric excess based on the nitric acid flow. The reactor operates adiabatically and gives 100% conversion of the nitric acid. All products leave the reactor as liquids at 138˚C. The sulphuric acid is re-concentrated to 66% and recycled, while the nitrobenzene is sent for purification.
(i) The temperature, X˚C of the mixed acids after mixing; (ii) The temperature, Y˚C, at which the mixed acids enter the reactor.
You may assume that the organics benzene and nitrobenzene form an ideal liquid mixture, and there is complete immiscibility between organics and inorganics.