Question

How many grams of iron(II) oxalate dihydrate, Fe(C2O4)·2H2O,mass can be produced when a student begins the synthesis with 3.238 g of ammonium iron(II) disulfate hexahydrate, (NH4)2Fe(SO4)2·6H2O?

Answer 1

The short way is this.
3.238 x (molar mass what of you want/molar mass of what you have) = ?