Question: What would a student report nearly after 30 minutes of placing duly cleaned strips of aluminium, copper, iron and zinc in freshly prepared iron sulphate solution taken in four beakers? [CBSE OD, Set 1, 2019]
Answer: Aluminium displaces the iron from iron sulphate and the colour of two solution changes from green to colourless. No change takes place when copper strip is dipped in iron sulphate solution. No change will be observed when iron strips are dipped in iron sulphate solution. The colour of the solution changes from green to colourless when zinc is added to iron sulphate solution.