Excess of $$KI$$  reacts with $$CuS{O_4}$$  solution and then $$N{a_2}{S_2}{O_3}$$   solution is added to it. Which of the statements is incorrect for this reaction ?

Solution :
$$\eqalign{ & 4\mathop {KI}\limits^{ - 1} + 2CuS{O_4} \to \mathop {{I_2}}\limits^0 + C{u_2}{I_2} + 2{K_2}S{O_4} \cr & \mathop {{I_2}}\limits^0 + \mathop {2N{a_2}{S_2}{O_3}}\limits^{2 + } \to \mathop {N{a_2}{S_4}{O_6}}\limits^{ - 2.5} + 2N\mathop {aI}\limits^{ - 1} \cr & {\text{In this}}\,Cu{I_2}\,{\text{is not formed}}{\text{.}} \cr} $$