What is the concentration of Ca2+ in a saturated solution of CaCO3 if its Ksp is 4.9 x 10^-9?

What is the concentration of Ca2+ in a saturated solution of CaCO3 if its Ksp is 4.9 x 10^-9?

• A. 2.4 x 10^-4 M
• B. 4.9 x 10^-5 M
• C. 7.0 x 10^-5 M
• D. 4.9 x 10^-9 M

Answer: (C)

To determine the concentration of Ca²⁺ in a saturated solution of calcium carbonate (CaCO₃), we start by writing the dissociation equation for the compound in water: CaCO₃ (s) ⇌ Ca²⁺ (aq) + CO₃²⁻ (aq) The solubility product constant (Ksp) for this equilibrium is given by the equation: Ksp = [Ca²⁺][CO₃²⁻] Let "s" be the solubility of CaCO₃ in moles per liter (M). In a saturated solution, the concentration of Ca²⁺ ions will be "s", and the concentration of CO₃²⁻ ions will also be "s", since they are produced in a 1:1 ratio when CaCO₃ dissolves. Thus, we can express the Ksp as: Ksp = s * s = s² Substituting the given Ksp value into this equation: 4.9 x 10^-9 = s² To find "s," we take the square root of both sides: s = √(4.9 x 10^-9) Calculating this gives: s

To determine the concentration of Ca²⁺ in a saturated solution of calcium carbonate (CaCO₃), we start by writing the dissociation equation for the compound in water:

CaCO₃ (s) ⇌ Ca²⁺ (aq) + CO₃²⁻ (aq)

The solubility product constant (Ksp) for this equilibrium is given by the equation:

Ksp = [Ca²⁺][CO₃²⁻]

Let "s" be the solubility of CaCO₃ in moles per liter (M). In a saturated solution, the concentration of Ca²⁺ ions will be "s", and the concentration of CO₃²⁻ ions will also be "s", since they are produced in a 1:1 ratio when CaCO₃ dissolves. Thus, we can express the Ksp as:

Ksp = s * s = s²

Substituting the given Ksp value into this equation:

4.9 x 10^-9 = s²

To find "s," we take the square root of both sides:

s = √(4.9 x 10^-9)

Calculating this gives:

s