A22.4 l high pressure reaction vessel is charged with 0.5020 mol of iron powder and 1.39 atm of oxygen gas at standard temperature. on heating, the iron and oxygen react according to the balanced reaction below. 4fe(s) + 3o2(g) → 2fe2o3(s) after the reaction vessel is cooled, and assuming the reaction goes to completion, what pressure of oxygen remains?

1.013 atm of oxygen remain.

Explanation:

4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)

If the problem asks us to calculate the pressure of oxygen remaining, it would mean that O₂ is the excess reactant, to confirm that:

The moles remaining of O₂ are equal to the original moles minus the reacting moles, which are calculated using the available moles of Fe:

Thus the remaining moles of O₂ are:

Finally we use PV=nRT again to calculate the new value of P:

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .