A thiosulfate ion solution was prepared by dissolving 4.5g of the Na2S2O3 compound. 5H2O in 250 ml of solution. A) calculate the concentration of thiosulfate ions S2O3 2 - in the solution.
B) 150 ML of a diiode solution A are diluted up to volume 250 ml. The B solution obtained is dosed by the thiosulfate solution prepared above. The equivalence is observed when 7.25 ml of the thiosulfate solution is added to 10 ml of solution B.
Calculate the diiode concentration of the solution A