Question

What is the molar solubility of BaSO₄ in a 0.250-M solution of NaHSO4? Ka for HSO₄− = 1.2 × 10–².

a) 1.2 × 10–² M
b) 2.4 × 10–³ M
c) 6.0 × 10–³ M
d) 3.0 × 10–³ M

Answer 1

The molar solubility of BaSO₄ in a 0.250-M solution of NaHSO₄ is 1.05 × 10⁻⁵ M. All options are incorrect.

Step-by-step explanation:

To determine the molar solubility of BaSO₄ in a 0.250-M solution of NaHSO₄, we need to consider the common ion effect. NaHSO₄ dissociates into Na⁺ and HSO₄⁻ ions in solution. HSO₄⁻ is the common ion with BaSO₄, which can decrease the solubility of BaSO₄.

To calculate the molar solubility, we need to compare the initial concentration of BaSO₄ with its solubility product, Ksp. Since the concentration of BaSO₄ is unknown, we can assume it to be 'x'.

Using the Ksp expression for BaSO₄, we can write: Ksp = [Ba²⁺][SO₄²⁻] = (x)(x) = x²

The Ksp value for BaSO₄ is given as 1.1 × 10⁻¹⁰. Setting up the equation: x² = 1.1 × 10⁻¹⁰

Solving for x, we find the molar solubility of BaSO₄ to be x = 1.05 × 10⁻⁵ M

Hence, none of the options are correct.