250. Please e-mail, and the material balance of the following reactions: SO2 + Br2 + H2O = HBr + H2SO4; Mg + H2SO4 = MgSO4 + H2 ; Cu + H2SO4 (conc.) = SuSO4 + SO2 + H2O ; J2 + KOH KJO3 + KJ + H2O.