Question

A conductivity cell has been calibrated with a 0.01 M, 1 : 1 electrolytic solution (specific conductance (κ = 1.25 × 10⁻³ S cm⁻¹) in the cell and the measured resistance was 800 Ω at 25°C. The cell constant is, ____________.

Options

• 10⁻¹ cm⁻¹

• 10¹ cm⁻¹

• 1 cm⁻¹

• 5.7 × 10⁻¹²

Answer 1

A conductivity cell has been calibrated with a 0.01 M, 1 : 1 electrolytic solution (specific conductance (κ = 1.25 × 10⁻³ S cm⁻¹) in the cell and the measured resistance was 800 Ω at 25°C. The cell constant is, 1 cm⁻¹.

Explanation:

R = `ρ. "l"/"A"`

cell constant = `"R"/ρ`

= `κ."R" (1/ρ = κ)`

= 1.25 × 10⁻³ Ω⁻¹ cm⁻¹ × 800 Ω

= 1 cm⁻¹