What is the final acetate ion concentration when 69. g Ba (C2H3O2) 2 is dissolved in enough water to make 970. mL of solution? The molar mass of Ba (C2H3O2) 2 is 255.415 g/mol.

0.28 M

0.64 M

0.91 M

0.20 M

0.56 M

0.56M

Explanation:

1. Dissociation equation

Assuming 100% dissociation, the equation is:

Ba (C₂H₃O₂) ₂ → Ba²⁺ + 2C₂H₃O₂⁻

↑

acetate ions

2. Molarity

Calculate the molarity, M, of the solution:

M = n / V (in liters)

n = mass in grams / molar mass

n = 69. g / 255.415g/mol = 0.27015 mol

M = 0.27015mol / 0.970liter = 0.27850 mol/liter ≈ 0.28M

3. Acetate ions

From the chemical equation, 1 mol of dissolved Ba (C₂H₃O₂) ₂ produces 2 acetate ions in solution.

Thus, 0.28 mol/liter * 2 = 0.56 mol/liter = 0.56M ← answer