Assertion (A): Magnesium can be obtained by the electronlysis of aqueous solution of `MgCl_(2)`.
Reason (R ): The electrode potential of `Mg^(2+)` is much higher than `H^(o+)`.

Options

A. If both `(A)` and `(R )` are correct and `(R )` is the correct explanation of `(A)`.
B. If both `(A)` and `(R )` are correct, but `(R )` is not the correct explanation of `(A)`.
C. If `(A)` is correct, but `(R )` is incorrect.
D. If `(A)` is incrrect, but `(R )` is correct.

Explanation

To solve the assertion and reasoning question, we will analyze both the assertion (A) and the reason (R) provided.

**Step 1: Analyze the Assertion (A)**
The assertion states that magnesium can be obtained by the electrolysis of an aqueous solution of MgCl₂.

- In electrolysis, ions in the solution are discharged at the electrodes. For magnesium (Mg²⁺) to be deposited at the cathode, it must have a lower discharge potential compared to the competing ions present in the solution, primarily H⁺ from water.

**Step 2: Analyze the Reason (R)**
The reason states that the electrode potential of Mg²⁺ is much higher than that of H⁺.

- The standard electrode potential for Mg²⁺/Mg is approximately -2.37 V, while for H⁺/H₂ it is 0.00 V. A higher (more positive) electrode potential means that the ion is less likely to be reduced (gain electrons) compared to an ion with a lower (more negative) potential. Therefore, in the presence of both Mg²⁺ and H⁺, H⁺ will be preferentially discharged at the cathode.

**Step 3: Conclusion**
Since the electrode potential of Mg²⁺ is indeed higher than that of H⁺, magnesium cannot be deposited from an aqueous solution of MgCl₂ during electrolysis. Instead, hydrogen gas will be evolved at the cathode.

- Thus, the assertion (A) is **incorrect** while the reason (R) is **correct**.

**Final Answer**: The assertion is false, and the reason is true. Therefore, the correct option is that the assertion is incorrect, and the reason is correct.

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