Question

Na₂SO₄ solution was slowly added to the solution consisting of 0.0100m Ba₂(aq) and 0.0100m S₂(aq). what concentration of SO₄²⁻ is required to initiate precipitation? (ignore the volume change. ksp of BaSO₄ is 1.1×10⁻¹⁰, and ksp of SrSO₄ is 3.2×10⁻⁷.)

Answer 1

The concentration of sulfate ion (SO₄²⁻) required to initiate precipitation in a solution with 0.0100 M Ba²⁺, using the Ksp of BaSO₄ (1.1×10⁻¹⁰), is 1.1×10⁻¸ M.

Step-by-step explanation:

To determine the concentration of sulfate ion (SO₄²⁻) required to initiate precipitation, we must use the solubility product constant (Ksp) for barium sulfate (BaSO₄). The Ksp for BaSO₄ is given as 1.1×10⁻¹⁰. To initiate precipitation, the product of the concentrations of the ions in solution ([Ba²⁺][SO₄²⁻]) must be equal to or greater than the Ksp. For a solution with 0.0100 M Ba²⁺, the concentration of SO₄²⁻ needed to reach the point of precipitation (Q) can be calculated using the equation:

Ksp = [Ba²⁺][SO₄²⁻]

Therefore, the required SO₄²⁻ concentration to start precipitation is:

[SO₄²⁻] = Ksp / [Ba²⁺]

[SO₄²⁻] = (1.1×10⁻¹⁰) / 0.0100

[SO₄²⁻] = 1.1×10⁻¸ M

Thus, a concentration of 1.1×10⁻¸ M sulfate ion is required to initiate precipitation of BaSO₄ when the barium ion concentration is 0.0100 M.