conductivity cell has two electrodes 20 mm apart and of cross section area 1.8 `cm^(2)`. Find the cell constant.

Explanation

To find the cell constant of a conductivity cell, we can use the formula:

\[ \text{Cell Constant (K)} = \frac{d}{A} \]

where:
- \(d\) is the distance between the electrodes (in cm),
- \(A\) is the cross-sectional area of the electrodes (in cm²).

### Step 1: Convert the distance from mm to cm
The distance between the electrodes is given as 20 mm. We need to convert this to centimeters.

\[ d = 20 \text{ mm} \times \frac{1 \text{ cm}}{10 \text{ mm}} = 2 \text{ cm} \]

### Step 2: Use the given cross-sectional area
The cross-sectional area is given as 1.8 cm².

\[ A = 1.8 \text{ cm}^2 \]

### Step 3: Calculate the cell constant
Now, we can substitute the values of \(d\) and \(A\) into the formula for the cell constant.

\[ K = \frac{d}{A} = \frac{2 \text{ cm}}{1.8 \text{ cm}^2} \]

### Step 4: Perform the calculation
Now, we perform the division:

\[ K = \frac{2}{1.8} \approx 1.111 \text{ cm}^{-1} \]

### Final Answer
The cell constant is approximately \(1.111 \text{ cm}^{-1}\).

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