Question

Rohan took 10 mL of freshly prepared iron sulphate solution in four different test tubes and added four different metal strips to each test tube as shown below :

ln test tubes I and llI, black residue was obtained while in test tubes ll and lV, no change was observed. Metals P, Q, R and S could be respectively 

(A) Al, Cu, Pb, As

(B) Pb, Cu, Ag, Al 

(C) Zn, Al, Cu, Ag 

(D) Zn, Cu, Al, Ag.

Answer 1

Correct option  (D) Zn, Cu, Al, Ag.

Explanation:

Black residue is obtained in test tubes I and lll i.e., iron gets displaced in test tubes I and lll. Therefore, metals P and R should be more reactive than iron.

No change is observed in test tubes ll and lV hence, metals Q and S should be less reactive than iron.