The unit of electro-chemical equivalent is

Options

A. gram
B. gram/ampere
C. gram/coulumb
D. coulumb/gram

Explanation

To find the unit of electrochemical equivalent, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Electrochemical Equivalent (E or Z)**:
- Electrochemical equivalent is defined as the mass of a substance deposited at an electrode when a certain amount of electric charge passes through the substance during electrolysis.

2. **Identify the Formula**:
- The formula for electrochemical equivalent is given by:
\[ Z = \frac{m}{Q} \]
where:
- \( Z \) = electrochemical equivalent,
- \( m \) = mass of the substance deposited (in grams),
- \( Q \) = electric charge passed (in coulombs).

3. **Determine the Units**:
- The unit of mass \( m \) is grams (g).
- The unit of electric charge \( Q \) is coulombs (C).

4. **Substitute the Units into the Formula**:
- By substituting the units into the formula, we get:
\[ Z = \frac{\text{grams}}{\text{coulombs}} = \text{grams per coulomb} \]

5. **Conclusion**:
- Therefore, the unit of electrochemical equivalent is:
\[ \text{grams per coulomb (g/C)} \]

### Final Answer:
The unit of electrochemical equivalent is **grams per coulomb (g/C)**.

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