The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric ac — Electrochemistry Chemistry Question
Question
The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric acid are 280, 860 and 426 S cm mol respectively. The molar conductivity at infinite dilution of barium sulphate is ................... S cm mol . (Round off to the Nearest Integer). 2 –1 2 –1
💡 Solution & Explanation
**Step 1: Identify the relevant ions** BaCl₂ provides Ba²⁺ and Cl⁻ ions H₂SO₄ provides H⁺ and SO₄²⁻ ions HCl provides H⁺ and Cl⁻ ions BaSO₄ would contain Ba²⁺ and SO₄²⁻ ions **Step 2: Apply Kohlrausch's Law of Independent Migration of Ions** Molar conductivity at infinite dilution equals the sum of ionic conductivities: Λ°(BaCl₂) = Λ°(Ba²⁺) + 2Λ°(Cl⁻) = 280 ... (1) Λ°(H₂SO₄) = 2Λ°(H⁺) + Λ°(SO₄²⁻) = 860 ... (2) Λ°(HCl) = Λ°(H⁺) + Λ°(Cl⁻) = 426 ... (3) **Step 3: Find Λ°(Ba²⁺) + Λ°(SO₄²⁻)** From equation (2): Λ°(H⁺) + Λ°(SO₄²⁻) = 430 From equation (3): Λ°(H⁺) + Λ°(Cl⁻) = 426 Subtracting (3) from (2): Λ°(SO₄²⁻) - Λ°(Cl⁻) = 4 **Step 4: Calculate Λ°(BaSO₄)** Λ°(BaSO₄) = Λ°(Ba²⁺) + Λ°(SO₄²⁻) From (1): Λ°(Ba²⁺) = 280 - 2Λ°(Cl⁻) From (3): Λ°