The conductivity of 0.001 mol L⁻¹ solution of CH₃COOH is 3.905 × 10⁻³ S cm⁻¹. Calculate its molar conductivity and degree of dissociation. Given: λ(H⁺) = 349.6 S cm² mol⁻¹ and λ(CH₃COO⁻) = 40.9 S cm² mol⁻¹. Define electrochemical cell. What happens if the external potential applied becomes greater than Ecell of the electrochemical cell?

(a) The conductivity, κ = 3.905 × 10⁻³ S/cm
The concentration, C = 0.001 M
The molar conductivity at given concentration, Λ = 1000κ/C = 1000 × 3.905 × 10⁻³ / 0.001 = 39.05 S cm²/mol
At infinite dilution, the molar conductivity, Λ₀ = λH⁺ + λCH₃COO⁻
Λ₀ = 349.6 + 40.9 = 390.5 S cm²/mol
The degree of dissociation, α = Λ/Λ₀ = 39.05/390.5 = 0.1
(b) An electrochemical cell is a device which is used to study the chemical reactions electrically. It consists of two electronic conductors such as metal plates or carbon rods dipped into an electrolytic or ionic conductor which is an aqueous electrolyte solution or a pure liquid of an electrolyte. Thus, an electrochemical cell is a device in which the decrease of free energy during an indirect redox reaction is made to convert chemical energy into electrical energy. If applied external potential becomes greater than Ecell of the electrochemical cell, then the electrochemical cell behaves as an electrolytic cell. All the chemical reactions will be reversed and electrical energy will be converted into chemical energy.