Which of the following relation is not correct?

Options

A. Equivalent conductivity `-S cm^(2) eq^(-1)`
B. Conductance `-ohm^(-1)`
C. Specific conductance -S cm
D. Cell constant `-cm^(-1)`

Answer

To determine which of the following relations is not correct, we need to analyze the units associated with each option provided in the question. Let's break down each option step by step.

### Step-by-Step Solution:

1. **Understanding Conductance**:
- Conductance (G) is the reciprocal of resistance (R).
- The unit of resistance is ohm (Ω), so the unit of conductance is ohm inverse (Ω⁻¹).

**Conclusion**: The first option regarding conductance being ohm inverse is correct.

2. **Understanding Specific Conductance (Conductivity)**:
- Specific conductance (κ) is the reciprocal of resistivity (ρ).
- The unit of resistivity is ohm-centimeter (Ω·cm), so the unit of specific conductance is ohm inverse centimeter inverse (Ω⁻¹·cm⁻¹) or siemens per centimeter (S/cm).

**Conclusion**: The second option regarding specific conductance being ohm inverse centimeter inverse is correct.

3. **Understanding Cell Constant**:
- The cell constant (K) is defined as the ratio of the length (l) of the electrode to the area (A) of the electrode.
- The unit of length is centimeter (cm) and the unit of area is square centimeters (cm²). Therefore, the unit of cell constant is cm/cm², which simplifies to cm⁻¹.

**Conclusion**: The third option regarding cell constant being centimeter inverse is correct.

4. **Understanding Equivalent Conductivity**:
- Equivalent conductivity (Λ) is defined as the conductivity of the solution multiplied by the dilution factor (which is often expressed in terms of normality).
- The unit of equivalent conductivity is siemens centimeter squared per equivalent (S·cm²/equiv), which can also be expressed as simon centimeter squared equivalent inverse (S·cm²·equiv⁻¹).

**Conclusion**: The fourth option regarding equivalent conductivity being simon centimeter squared equivalent inverse is correct.

### Final Conclusion:
After analyzing all the options, we find that all options are correct except for the specific conductance option, which is stated incorrectly in the context of the question. Therefore, the option that is not correct is:

**Correct Option**: Option 3 (Specific Conductance).