3 possible limiting reactants for the equation H2S +2FeS + CO2 ⇒ HCO2H + Fe2S3 ( + S ) (possibly)
Since the need for H2S and CO2 is 1:1 in moles and we know that CO2 weighs more, the CO2 is limiting given equal mass in the feed. The Fe in the FeS is oxidized and may be required or not (as elemental S could be formed as well, in which case the FeS may not be limiting if it is all turned) Oddly enough, it is the LR for the reaction above if it is required as stated. Also, its given amount is just about necessary for 51% yield from the CO2
I'm going to assume the CO2 is limiting:
1.98 g CO2 (1 mole/44.01 g CO2)( 1 mole HCO2H/1 mole CO2)(46.026 g/mole HCO2H)(51 g act/100 g theory) = g of HCO2H
If the FeS is Limiting, the calculation is similar.
Please consider a tutor. Take care.