Question

Will a reaction occur, if zinc granules are dropped in sodium sulphate solution?

Answer 1

Hint: Only possible reaction that can occur here is a redox reaction and that will depend on following values. Zinc half cell has a standard electrode potential of -0.76V and Sodium half cell has a standard electrode potential of -2.71V.

Complete Step-by-Step Solution:
Here, we can see that Zinc metal is allowed to react with sodium sulphate solution, now there is only one possibility of reaction and that is a redox reaction.
\[Z{n_{(s)}} + N{a_2}S{O_4}\xrightarrow{{{\text{Redox reaction}}}}?\]
 We will need to predict whether this reaction will occur or not. Let’s see the reasons why it will not occur.
- If a redox reaction will occur there, then zinc will get oxidized from (0) to (+2) oxidation state and sodium will get reduced from (+1) to (0) oxidation state. Now, this reaction can be predicted by the standard potential value of the half cells that are given to us.
- Zn half cell has a standard potential value of -0.76V and Sodium half cell has standard potential value of -2.71V.
- We know that the standard potential of the half cell is the reduction potential of the half cell and hence higher the value of the reduction potential, higher will be the tendency of the species to get reduced. So, we can see that here Zinc has higher value of reduction potential so it will get reduced and sodium will get oxidized. We have the same condition here. So, the reaction will not occur.
Hence we can say that no reaction will occur when Zinc granules will be dropped in a solution of sodium sulphate.

Additional Information:
- Below are the half cell reactions for Zinc and sodium.
\[Z{n^{2 + }}_{(s)} + 2{e^ - }\xrightarrow{{reduction}}Z{n_{(s)}}\] (-0.76V)
\[N{a^ + }_{(s)} + {e^ - }\xrightarrow{{reduction}}N{a_{(s)}}\] (-2.71V)

Note: Remember the fact that the species that has higher reduction potential, gets reduced and if it is present in the solution already in its reduced form, then it will not undergo oxidation reaction and will be in the form as it was. Do not get confused with oxidation potential and standard potential of the half cell.