Answer to Question #159118 in General Chemistry for Dexther Villanueva

Question

An excess of potassium iodide is added to a solution of potassium dichromate, and the liberated iodine is titrated with 48.80ml of 0.1000M sodium thiosulfate solution. How many grams of K2Cr2O7 did the dichromate solution contain?

Answer 1

K₂Cr₂O₇ + 6 KI + 7 H₂SO₄ → 4 K₂SO₄ + Cr₂(SO₄)₃ + 3 I₂ + 7 H₂O

2Na2S2O3 + J2 → Na2S4O6 + 2NaJ  

0.0488x0.1/2 = 0,00244.

0,00244 x 2 x 294/6= 0,23912 g.