Sulfur dioxide (SO2\text{SO}_2SO2) is used as a preservative in winemaking. The concentration of sulfur dioxide in white wine can be determined by titration with aqueous iodine, I2(aq)\text{I}_2(aq)I2(aq).
A chemist titrated a 25.0 cm325.0\text{ cm}^325.0 cm3 sample of white wine, which reacted with exactly 16.00 cm316.00\text{ cm}^316.00 cm3 of 0.0025 mol/dm30.0025\text{ mol/dm}^30.0025 mol/dm3 aqueous iodine.
The chemical equation for the reaction is:
SO2(aq)+I2(aq)+2H2O(l)→SO42−(aq)+2I−(aq)+4H+(aq) \text{SO}_2(aq) + \text{I}_2(aq) + 2\text{H}_2\text{O}(l) \rightarrow \text{SO}_4^{2-}(aq) + 2\text{I}^-(aq) + 4\text{H}^+(aq) SO2(aq)+I2(aq)+2H2O(l)→SO42−(aq)+2I−(aq)+4H+(aq)Calculate the amount, in moles, of iodine in 16.00 cm316.00\text{ cm}^316.00 cm3 of a 0.0025 mol/dm30.0025\text{ mol/dm}^30.0025 mol/dm3 solution.
Deduce the amount, in moles, of sulfur dioxide in the 25.0 cm325.0\text{ cm}^325.0 cm3 sample of white wine.
Calculate the concentration, in mol/dm3\text{mol/dm}^3mol/dm3, of sulfur dioxide in the white wine.
Calculate the concentration, in g/dm3\text{g/dm}^3g/dm3, of sulfur dioxide in the white wine. (Relative atomic masses: O=16.0\text{O} = 16.0O=16.0, S=32.1\text{S} = 32.1S=32.1)
A regulation states that "organic" white wine must contain no more than 0.15 g/dm30.15\text{ g/dm}^30.15 g/dm3 of sulfur dioxide to be certified organic.
Use the value you have calculated in (d) to state whether this wine can be certified as "organic".
