A 3:2 molar ratio mixture of FeO and Fe2O3 reacts with oxygen to produce a 2:3 molar ratio mixture of FeO and Fe2O3. Find the mass (in g) of O2 gas required per mole of the initial mixture.​

Total moles  of initial mixtures =5
3 moles of FeO plus two moles of Fe2O3
Fe2O3 has Fe already in highly oxidized form. Fe2O3
Now only FeO will react with oxygen to form Fe203 - balance equation
4FeO +O2   ----> 2Fe2O3

During reaction the mixture ratio changes from 3FeO : 2 Fe2O3  to 2FeO:3 Fe2O3
It means 1 mole FeO has reacted with oxygen
In balanced equation one mole of FeO needs one by fourth mol of O2 which means only 8 gram
We can say that initial 5 moles of the mixture needs 8 grams of oxygen so one mol of mixture  will need 8 divided by 5  means 1.6g