A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate. In which test tube or test tubes will she observe colour change ? On the basis of this experiment, state which one is the most reactive metal and why.
Thus, colour change observed in A, B and D.
Since aluminium displaces both the elements, it is the most reactive elements among all. It is above both the elements in activity series.