In a cell reaction, `Cu_((s))+ 2Ag_((aq))^(+) to Cu_((aq))^(2+) + 2Ag_((s)) E_"cell"^@`=+0.46 V . If the concentration of `Cu^(2+)` ions is doubled then `E_"cell"^@` will be

Options

A. doubled
B. halved
C. increased by four times
D. unchanged.

Explanation

To solve the problem, we need to understand the relationship between the standard cell potential (E°cell) and the concentrations of the reactants and products in an electrochemical cell.

### Step-by-Step Solution:

1. **Identify the Reaction**: The given cell reaction is:
\[ \text{Cu}_{(s)} + 2\text{Ag}^{+}_{(aq)} \rightarrow \text{Cu}^{2+}_{(aq)} + 2\text{Ag}_{(s)} \]
The standard cell potential (E°cell) for this reaction is given as +0.46 V.

2. **Understand Standard Cell Potential**: The standard cell potential (E°cell) is a constant value that does not change with the concentration of the reactants or products. It is determined under standard conditions (1 M concentration, 1 atm pressure, and 298 K temperature).

3. **Effect of Concentration Change**: The problem states that the concentration of Cu²⁺ ions is doubled. However, since E°cell is a standard value, it remains unchanged regardless of the concentration changes in the reactants or products.

4. **Conclusion**: Since E°cell is independent of concentration changes, even if the concentration of Cu²⁺ is doubled, the standard cell potential remains the same at +0.46 V.

### Final Answer:
The standard cell potential \( E°_{cell} \) will remain unchanged at +0.46 V.

---