Answer:
3.228x10⁻⁴ moles of Na2S2O3 are required
Explanation:
In iodometry, the reaction of KIO3 with Na2S2O3 is:
KIO3 + 6 Na2S2O3 + 6H⁺ → KI + 3Na2S4O6 + 3H2O + 6Na⁺
Where 6 moles of Na2S2O3 reacts per moles of KIO3.
The moles of Na2S2O3 required to reach endpoint when 0.0000538 moles of KIO3 are:
0.0000538 moles of KIO3 * (6 moles Na2S2O3 / 1 mol KIO3) =