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The standerd potential at 25^(@) for the...

The standerd potential at `25^(@)` for the following Half rection is given :
`Zn^(2+)+2e^(-)toZn,E^(@)=-0.762 V`
`Mg^(2+)+2e^(-)toMg,E^(@)=-2.37 V`
When Zinc dust is added to the solution of `MgCl_(2)`.

A

`ZnCl_(2)` is formed

B

Mg is percipitaed

C

Zn dissolved in the solution

D

No reaction take place

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the addition of zinc dust to a solution of MgCl₂, we will analyze the standard reduction potentials given and apply our understanding of electrochemical series. ### Step-by-Step Solution: 1. **Identify the Half-Reactions and Their Standard Potentials**: - The half-reaction for zinc is: \[ \text{Zn}^{2+} + 2e^- \rightarrow \text{Zn} \quad E^\circ = -0.762 \, \text{V} \] - The half-reaction for magnesium is: \[ \text{Mg}^{2+} + 2e^- \rightarrow \text{Mg} \quad E^\circ = -2.37 \, \text{V} \] 2. **Understand the Electrochemical Series**: - In the electrochemical series, metals are arranged according to their standard reduction potentials. A higher (less negative) reduction potential indicates a stronger tendency to gain electrons (be reduced). - Here, zinc has a higher reduction potential (-0.762 V) compared to magnesium (-2.37 V). This means zinc is more likely to be reduced than magnesium. 3. **Determine the Oxidation Potentials**: - The oxidation potential is the negative of the reduction potential. Therefore: - For zinc: \[ \text{Zn} \rightarrow \text{Zn}^{2+} + 2e^- \quad E_{\text{oxidation}} = +0.762 \, \text{V} \] - For magnesium: \[ \text{Mg} \rightarrow \text{Mg}^{2+} + 2e^- \quad E_{\text{oxidation}} = +2.37 \, \text{V} \] 4. **Compare the Oxidation Potentials**: - Since magnesium has a higher oxidation potential than zinc, magnesium can displace zinc from its compounds. However, zinc cannot displace magnesium due to its lower oxidation potential. 5. **Conclusion on the Reaction**: - When zinc dust (solid zinc) is added to a solution of MgCl₂, no reaction occurs because zinc cannot displace magnesium from its ionic form in the solution. Thus, the answer to the question is that **no reaction takes place**. ### Final Answer: **No reaction takes place when zinc dust is added to the solution of MgCl₂.**
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