X is a divalent metal. The value of its electrochemical equivalent is `5.25xx10^(-4)`g. Its atomic mass will be:

Options

A. `310.74` u
B. `101.32` u
C. `126.9` u
D. `15.87` u

Answer

To find the atomic mass of the divalent metal X given its electrochemical equivalent (ECE), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula**: The electrochemical equivalent (E) is given by the formula:
\[ E = \frac{\text{Equivalent weight}}{F} \]
where \( F \) is Faraday's constant (approximately \( 96500 \, C/mol \)).

2. **Relate Equivalent Weight to Atomic Mass**: For a divalent metal, the equivalent weight can be expressed as:
\[ \text{Equivalent weight} = \frac{\text{Atomic mass}}{n} \]
where \( n \) is the number of electrons transferred per ion (for a divalent metal, \( n = 2 \)).

3. **Substituting into the Formula**: We can substitute the equivalent weight into the ECE formula:
\[ E = \frac{\frac{\text{Atomic mass}}{2}}{F} \]

4. **Rearranging the Formula**: Rearranging the formula to solve for atomic mass gives us:
\[ \text{Atomic mass} = E \times F \times n \]

5. **Plugging in the Values**: Given:
- \( E = 5.25 \times 10^{-4} \, g \)
- \( F = 96500 \, C/mol \)
- \( n = 2 \)

We can substitute these values into the equation:
\[ \text{Atomic mass} = (5.25 \times 10^{-4}) \times 96500 \times 2 \]

6. **Calculating the Atomic Mass**:
\[ \text{Atomic mass} = (5.25 \times 10^{-4}) \times 96500 \times 2 = 1.01325 \times 10^{3} \, g \]
\[ = 101.325 \, g \]

7. **Final Result**: Rounding to two decimal places, the atomic mass of metal X is:
\[ \text{Atomic mass} \approx 101.32 \, g \]

### Conclusion:
The atomic mass of the divalent metal X is approximately **101.32 g**.