What mass (in grams) of iron is required to react with 7.0 L of oxygen at 1 atm and 0ºC in order to produce Fe3O4 according to the balanced equation below

26.18 g

Explanation:

The molar volume of oxygen at 1 atm and 0ºC is 22.4 L/mol.

If you want to react 7 L it means you will use

7/22.4 = 0.3125 moles of oxygen

the balanced equation is 3 Fe + 2 O2 = Fe3O4

which means that 2 moles of oxygen reacts with 3 moles of iron

If you have 0.3125 moles of oxygen, 0.468 moles of iron will be needed.

Iron molecular weight is 55.84 and than, 0.3125 moles corresponds to a mass of iron equal to 26.18