A student weighs 0.1470 g of pure potassium dichromate, with a molar mass of 294 g/mol…

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A student weighs $0.1470\ \text{g}$ of pure potassium dichromate, with a molar mass of $294\ \text{g/mol}$ . It is dissolved, and acid and excess potassium iodide are added: $\text{Cr}_2\text{O}_7^{2-} + 6\text{I}^- + 14\text{H}^+ \rightarrow 2\text{Cr}^{3+} + 3\text{I}_2 + 7\text{H}_2\text{O}$ . The iodine that forms needs $29.4\ \text{mL}$ of sodium thiosulfate solution, by $\text{I}_2 + 2\text{S}_2\text{O}_3^{2-} \rightarrow 2\text{I}^- + \text{S}_4\text{O}_6^{2-}$ . Find the amount of dichromate, the amount of iodine and the concentration of the thiosulfate solution.

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