Molarity General Chem

Question

Determine the molarity of 3.80 g KMnO₄ in 225.3 mL solution

Answer 1

Molar mass KMnO4 = 158.0 g / mole

Volume of solution = 225.3 ml x 1 L / 1000 ml = 0.2253 L

Molarity = moles of solute / liter of solution

We know the liters of solution (0.2253 L), so we need to find the moles of solute

Moles of solute = 3.80 g KMnO4 x 1 mol / 158.0 g = 0.02405 moles

Molarity = 0.02405 moles / 0.2253 L = 0.1067 M = 0.107 M (3 s.f.)