Which relation is correct?

Options

A. Molar conductance = conductivity `xx` concentration
B. Equivalent conductance `= ("Conductivity")/("Volume")`
C. Cell constant `=("Conductivity")/("Conductance")`
D. Conductance = specific conductivity `xx` cell constant

Answer

To determine which relation is correct among the given options, we will analyze each of the provided statements step by step.

### Step 1: Understanding Conductance and Resistance
- Conductance (G) is the reciprocal of resistance (R), given by the formula:
\[ G = \frac{1}{R} \]
- Resistance is related to the dimensions of the conductor:
\[ R = \frac{l}{A \cdot \sigma} \]
where \( l \) is the length, \( A \) is the area of cross-section, and \( \sigma \) is the conductivity.

### Step 2: Relating Conductivity and Conductance
- The conductivity (k) can be expressed in terms of conductance (G) and the cell constant (C):
\[ k = G \cdot C \]
where the cell constant \( C \) is defined as:
\[ C = \frac{l}{A} \]

### Step 3: Analyzing the Options
1. **Option A**: Molar conductance \( \Lambda_m = k \cdot C \)
- This is incorrect. The correct relation is:
\[ \Lambda_m = \frac{k}{c} \]
where \( c \) is the concentration.

2. **Option B**: Equivalent conductance \( \Lambda_{eq} = k \cdot V \)
- This is also incorrect. The correct relation is:
\[ \Lambda_{eq} = \frac{k \cdot 1000}{N} \]
where \( N \) is the normality.

3. **Option C**: Cell constant \( C = \frac{k}{G} \)
- This is correct as derived from the relation \( k = G \cdot C \).

4. **Option D**: Conductance \( G = k \cdot C \)
- This is incorrect as it confuses the definitions.

### Conclusion
The only correct relation among the options given is:
\[ \text{Option C: Cell constant } C = \frac{k}{G} \]