1. How many moles of CuO are needed to react with 5.9 moles of CO2 2CuO-C--->2Cu+CO2

2. How many moles of Fe2O3 were used to produce with 11.5 moles of CO2
3Fe2O3+CO--->2Fe3O4+CO2

3.If 6.3 moles of CO2 were produced, how many moles of O2 were used?
CH4=202>CO2+2H2O

Please help.