Which of the following reaction is not observed when Al is added to a solution of copper sulphate ?

When Al is added to a solution of copper sulphate then blue coloured copper sulphate in the beginning changes to colourless solution at the ending. Because highly reactive Al replaces least reactive copper from copper sulphate solution as per metal activity series. Brown coloured Cu is deposited on Al.

$2A{l}_{\left(s\right)}+\underset{Blue}{3CuS{O}_{4\left(aq\right)}}\to \underset{Colourless}{A{l}_2{\left(S{O}_4\right)}_{3\left(aq\right)}}+\underset{Brown}{3C{u}_{\left(s\right)}}$