What is the molarity of a potassium triiodide solution,KI₃(aq),if 30.00 mL of the solution is required to completely react with 25.00 mL of a 0.500 M thiosulfate solution,K₂S₂O₃(aq)? The chemical equation for the reaction is: 2 S₂O₃^2-(aq)+ I₃^-(aq)→ S₄O₆^2-(aq)+ 3 I^-(aq).

Question

Quizplus · Accepted Answer

The balanced equation shows that 2 moles of thiosulfate react with 1 mole of triiodide. Using the volume and molarity of thiosulfate, calculate moles of thiosulfate: 0.025 L * 0.500 M = 0.0125 moles. Thus, moles of I3- = 0.0125 / 2 = 0.00625 moles. Molarity of KI3 = 0.00625 moles / 0.030 L = 0.208 M.

What Is the Molarity of a Potassium Triiodide Solution,KI3(aq),if 30

What Is the Molarity of a Potassium Triiodide Solution,KI₃(aq),if 30