Question

Four test tubes were taken and marked 1,2,3 and 4 respectively. 2 mL of aqueous solution of aluminium sulphate, Al₂(SO₄)₃ was filled in each test tube. A piece of metal zinc was placed in test tube 1, iron in test tube 2, copper in test tube 3 and aluminium in test tube 4. Mark the correct change in colour in the four test tubes.

Answer 1

Correct option (D)  

Explanation:

As per the reactivity series, reactivity of metals is Al > Zn > Fe > Cu.

As Zn, Fe and Cu, all are less reactive than Al so, they do not displace Al from Al₂(SO₄)s solution hence, all the solutions remain colourless. There is no effect observed in test tube 4 as AI is dipped in its own salt solution.