(Solved): 9. Sulfur dioxide, SO2, is used in wine as an antioxidant, slowing 1 point the oxidation of etha ...

9. Sulfur dioxide, ${\mathrm{SO}}_2$, is used in wine as an antioxidant, slowing 1 point the oxidation of ethanol to ethanoic acid. To determine the ${\mathrm{SO}}_2$ content of a wine sample, sodium hydroxide $(\mathrm{NaOH})$ and sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ were added to ensure that all sulfur was present as ${\mathrm{SO}}_2.\mathrm{A}20.00\mathrm{mL}$ aliquot (portion) was then titrated against standardized iodine solution $\left({\mathrm{I}}_2\right)$, using starch indicator Reaction occurred according to the equation: ${\mathrm{SO}}_2(\mathrm{aq})+2{\mathrm{H}}_2\mathrm{O}(\mathrm{l})+{\mathrm{I}}_2(\mathrm{aq})?2\mathrm{rarrjpg}4{\mathrm{H}}^{+}(\mathrm{aq})+2{\mathrm{I}}^{?}(\mathrm{aq})+{\mathrm{SO}}_4{}^{2?}(\mathrm{aq})$ The end point was reached with $15.62\mathrm{mL}$ of $0.00501\mathrm{M}$ iodine solution. The concentration (in M) of ${\mathrm{SO}}_2$ in the $20.0\mathrm{mL}$ sample of wine was $32\times 10^{?3}$ $7.8\times 10^{?3}$ $3.9\times 10^{?3}$ $50\times 10^{?3}$