Potassium iodate tablets can be used as a dietary iodine supplement. The mass of potassium iodate(V), KIO3\text{KIO}_3KIO3, in a tablet can be determined by reacting it with an aqueous solution of potassium iodide, KI\text{KI}KI, in the presence of acid.
IO3−(aq)+5I−(aq)+6H+(aq)→3I2(aq)+3H2O(l) \text{IO}_3^-(\text{aq}) + 5\text{I}^-(\text{aq}) + 6\text{H}^+(\text{aq}) \rightarrow 3\text{I}_2(\text{aq}) + 3\text{H}_2\text{O}(\text{l}) IO3−(aq)+5I−(aq)+6H+(aq)→3I2(aq)+3H2O(l)A student finds that three KIO3\text{KIO}_3KIO3 tablets react with exactly 35.0 cm335.0\text{ cm}^335.0 cm3 of 0.120 mol dm−30.120\text{ mol dm}^{-3}0.120 mol dm−3 KI\text{KI}KI.
Calculate the mass, in mg, of KIO3\text{KIO}_3KIO3 in one tablet. Use the following relative atomic masses: K=39.1\text{K} = 39.1K=39.1, I=126.9\text{I} = 126.9I=126.9, O=16.0\text{O} = 16.0O=16.0.
Give your answer to the nearest whole number.
199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.