Question

the solution of Znso4 ,Feso4,Cuso4 are taken in three different test tubes.suppose ,an iron nail is kept immersed in each one
(a) in which test tube irono nail undergoes a colour change?

Answer 1

Iron nail undergoes a colour change in the test tube of copper sulfate.

• Iron is more reactive than Cu so, it can easily displace Cu from copper sulfate and produces iron sulfate.
• The reaction is as follows-
• $CuSO_4+Fe\rightarrow FeSO_4+Cu$.
• Here the brown colour of Fe changes to green colour due to the formation of iron sulfate.
• Zn is more reactive than Fe so, Fe can not displace Zn. Thus no colour change is observed.