Based on the balanced chemical equation shown below,what volume of 0.250 M K₂S₂O₃₍_aq₎ is needed to completely react with 12.44 mL of 0.125 M KI₃(aq)? 2 S₂O₃^2-(aq)+ I₃^-(aq)→ S₄O₆^2-(aq)+ 3 I^-(aq) A)3.11 mL B)6.22 mL C)12.4 mL D)49.8 mL

Question

Quizplus · Accepted Answer

First, use the balanced chemical equation to determine the mole ratio between KI and Na2S2O3:

1 mol KI reacts with 2 mol Na2S2O3

Then, use the concentration and volume of KI to calculate the number of moles present:

moles KI = concentration x volume = 0.125 M x 12.44 mL x (1 L / 1000 mL) = 0.001555 mol

Finally, use the mole ratio to determine the volume of Na2S2O3 needed:

moles Na2S2O3 = (0.001555 mol KI) x (2 mol Na2S2O3 / 1 mol KI) = 0.00311 mol

volume Na2S2O3 = moles / concentration = 0.00311 mol / 0.250 M = 0.0124 L = 12.4 mL

Therefore, the best choice is C, 12.4 mL.

Based on the Balanced Chemical Equation Shown Below,what Volume of 0.250