g Calculate the concentration of sulfate ion when BaSO4 just begins to precipitate from a solution that is 0.0758 M in Ba2+.

1.42 × 10⁻⁹ M

Explanation:

Step 1: Given data

Step 2: Write the reaction for the solution of BaSO₄

BaSO₄(s) ⇄ Ba²⁺(aq) + SO₄²⁻(aq)

Step 3: Calculate the concentration of SO₄²⁻

We will use the following expression.

Ksp = 1.08 × 10⁻¹⁰ = [Ba²⁺] × [SO₄²⁻]

[SO₄²⁻] = 1.08 × 10⁻¹⁰ / [Ba²⁺] = 1.08 × 10⁻¹⁰ / 0.0758 = 1.42 × 10⁻⁹ M

the product of the pressure and volume is also constant

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.