How many milliliters of 0.200 M FeCl3 are needed to react with an excess of Na2S to produce 0.690 g of Fe2S3 if the percent yield for the reaction is 65.0 percent
3 Na2S aq plus 2 FeCl3 aq arrow Fe2S3 s plus 6 NaCl aq
25.5 mL
51.1 mL
12.8 mL
21.6 mL?
