Hello,
First you need to make sure that the equation in balanced in this problem and any problems similar to this. The equation balanced is : 2 IrCl3 + 3 NaOH → Ir2O3 + 3 HCl + 3 NaCl
Now using the mole ratio information, it is telling you that for every 2 moles of IrCl3 used, one mole of Ir2O3 will be produced.
The amount of reactant is given in grams and you should know how to get moles of a reactant from grams (÷ by the molar mass).
The steps are : g reactant → mol reactant →mol product → g product
with each arrow representing a step using a conversion relationship.
199 g IrCl3 (1 mol IrCl3/ 299 g IrCl3) ( 1 mol Ir2O3/ 2 mol IrCl3) ( 432 g Ir2O3 / 1 mol Ir2O3) = 144 g
You can use the above information to help solving any problem similar to this one.
All the best!