Question

Consider five different test tubes labeled as (a), (b), (c), (d) and (e) contain aqueous solution of AgNO3, NaOH, Al 2 (SO 4 ) 3, Pb (NO 3 ) 2 and NaCl
respectively. Zinc granules are added in each test tube and the test tubes are observed for sometime. Which of the following options is true?
Consider five different test tubes denoted by (a), (b), (c), (d) and (e) in which AgNO3, NaOH, Al 2 (SO 4 ) 3. Pb (NO 3 ) 2 respectively.And are aqueous
solutions of NaCl. Granulated zinc was added to each test tube and test tubes were observed for some time. Which of the following options is correct?

Answer 1

Four students A, B, C and D took aqueous solutions of zinc sulphate and iron sulphate in two test tubes I and II and dropped metal pieces of Iron and Zinc in the two solutions. After several hours, they made observations and recorded their findings in the form of a table given below:

Observation Metal Solution Change in colour of the solution Deposit/Residue obtained

By A Fe ZnSO

4

turned green Silver grey coating

Zn FeSO

4

no change no change

By B Fe ZnSO

4

no change black residue

Zn FeSO

4

colour faded grey coating

By C Fe ZnSO

4

no change no change

Zn FeSO

4

turned colourless black residue

By D Fe ZnSO

4

no change grey residue

Zn FeSO

4

no change

Observation of student C are correct as Fe cannot displace Zn from its ZnSO4

Observation of student C are correct as Fe cannot displace Zn from its ZnSO4