Question

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.

Answer 1

In activity series, the elements on the top can displace element at the bottom but not vice versa. From the given question, Aluminium can displace iron and copper sulphate solutions. Hence, colour change will be observed in Test-Tube A and Test-tube B. Iron metal cannot displace aluminium but can displace copper sulphate solution. Hence Test-tube D’s colour will change too.

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 the activity series.