Out of the following matals that cannot be obtained by electrolysis of the aquenous solution of their salts is

Options

A. Ag
B. Mg
C. Cu
D. Al

Explanation

To solve the question of which metal cannot be obtained by electrolysis of their aqueous solution of their salts, we can follow these steps:

### Step 1: Understand the Electrolysis Process
Electrolysis involves the breakdown of a compound into its elements using electricity. In the case of aqueous solutions, both the metal ions and hydrogen ions (H⁺) are present.

**Hint:** Remember that during electrolysis, the ions present in the solution compete for reduction at the cathode.

### Step 2: Identify the Reactivity Series
The reactivity series ranks metals based on their ability to displace hydrogen from acids and their tendency to be reduced. Metals that are more electropositive than hydrogen will not be reduced at the cathode during electrolysis of their aqueous salts.

**Hint:** Metals above hydrogen in the reactivity series are less likely to be reduced than hydrogen ions.

### Step 3: Analyze the Given Metals
Consider the metals in the question:
- **Magnesium (Mg)**
- **Aluminum (Al)**
- **Copper (Cu)**
- **Silver (Ag)**

**Hint:** Check where each metal stands in relation to hydrogen in the reactivity series.

### Step 4: Determine Reduction Potentials
- Magnesium and aluminum are more electropositive than hydrogen, meaning they will not be reduced at the cathode. Instead, H⁺ ions will be reduced to hydrogen gas.
- Copper and silver are less electropositive than hydrogen, so they can be reduced from their aqueous solutions.

**Hint:** Focus on the reduction potential; metals with lower reduction potentials than hydrogen can be reduced.

### Step 5: Conclusion
Since magnesium and aluminum cannot be obtained by electrolysis of their aqueous solutions due to their higher reactivity compared to hydrogen, the correct answer to the question is that these metals cannot be obtained by electrolysis.

### Final Answer
The metals that cannot be obtained by electrolysis of their aqueous solution of their salts are **Magnesium (Mg)** and **Aluminum (Al)**.

---