I think it is easy to calculate: You just need to know the Gibbs free energy of formation of the reactant (the H2SO4) and the products (the H+ and the SO4 2-). Then you can calculate the energy released for the process.
Ok thank you, I got a graph that can give the value, We dilute 98% Sulphuric to 38% in a 10 000L batch. I just wanted to estimate few things.Thanks everyone