DrBob222 : Chemistry HElp...Please Check
posted by Sara .
Sorry its not letting me post the entire thing in the other thread
.000146612 mols KIO3 x (3 mols I2/1 mol KIO3) x (2 mols S2O3^-2/1 mol I2) mols
= .000887972 mols S203^2-
Then M S2O3^-2 = .000887972 mols/0.02715 L.M = 0.032400
Therefore the Molar mass of Na2S2O3 is 0.032400
You don't mean the molar mass is 0.03240, you mean the molarity is 0.03240. I get the same figures you do. So the solution of Na2S2O3 is 0.03240 M. By the way, I think you are limited to just the one zero as I have it written and not 0.032400. Since the 27.15 mL, 25.00 mL aliquot, 0.1255 g KIO3 all have four significant figures, you can have no more than that in the answer.
Oh okay that you...and yes i meant molarity