The ratio of the solubility of BaSO₄ in pure water to its solubility in a 0.1 M Na₂SO₄ solution is: (Given : Solubility product of BaSO₄ = 10⁻¹⁰ )

Step-by-step solution

Let the solubility of BaSO₄ in pure water be s₁ . For a 1:1 salt, K_ sp = s₁^2 s₁ = 10⁻¹⁰ = 10⁻⁵ M Let the solubility of BaSO₄ in 0.1 M Na₂SO₄ be s₂ . Due to the common ion effect from SO₄²⁻ , the concentration of SO₄²⁻ is approximately 0.1 M . K_ sp = [ Ba²⁺ ][ SO₄²⁻ ] = s₂ 0.1 10⁻¹⁰ = s₂ 10⁻¹ s₂ = 10⁻⁹ M The required ratio is s₁ s₂ = 10⁻⁵ 10⁻⁹ = 10^4 . Answer: 10⁴