Aqueous solution of CuSO4 is electrolysed using inert electrodes till the blue coloured solution becomes colourless. The colourless solution formed is

At CathodeSRP of Cu+2  > SRP of H2O.   Cu+2 undergoes reduction.At AnodeH2O readily undergoes OxidationIn the Vessel H+ reacts with and forms colorless solution H2SO4