The following reaction is used to prepare iodine:
2NaI (s) + 2H_2_SO_4 (aq) + MnO_2 ----------> Na_2_SO_4 (aq) + MnSO_4 + I_2 (g) + 2H_2_O (I)
What quantity of iodine can be obtained when 20.0 grams of NaI are mixed with 10.0 grams of MnO_2 and an excess of sulfuric acid?