Pls ans fast.....urgent
Q) 20
Q.20. A student working in the laboratory kept an aqueous solution of ferrous sulphate in a vessel made up of zinc. After a few days, he found that vessel had developed holes and Cracks.
a) Why did the vessel develop holes in it?
b) Name the type of redox reaction and mention the balanced chemical reaction involved in it.
c) What is the value associated with this?

Dear Student,

When ferrous sulphate is kept in zinc vessel, after sometime it undergo a redox reaction. And the crack and hole is created.
(i) This hole is developed due to the oxidation of zinc forming the zinc sulphate and hence the degradation of vessel takes place.
         The reaction takes place: 
                                          $$\begin{gathered} FeS{O}_4 +\hspace{0.17em}Zn \stackrel{}{\to }Fe +\hspace{0.17em}ZnS{O}_4 \\ +2 0 0 +2 \end{gathered}$$

(ii) The redox reaction taking place in this chemical reaction is the displacement reaction. In this more active zinc metal displaces less reactive iron metal salt.
The balanced reaction is as follows: 
                                  ​$$\begin{gathered} FeS{O}_4 +\hspace{0.17em}Zn \stackrel{}{\to }Fe +\hspace{0.17em}ZnS{O}_4 \\ +2 0 0 +2 \end{gathered}$$

(iii) As there is the change in oxidation number of iron and iron sulphate and zinc and zinc sulphate by two. 
Hence the value asssociated with this is 2.

Regards.