I am currently studying gaseous state and I encountered the following problem.
A container with a volume 3 liter holds NX2(g)NX2(g) and HX2O(l)HX2O(l) at 29 ∘C29 ∘C. The pressure is found to be 1 atm1 atm. The water is then split into hydrogen and oxygen by electrolysis according to the reaction
HX2O(l)⟶HX2(g)+12OX2(g)HX2O(l)⟶HX2(g)+12OX2(g) After the reaction is complete, the pressure is 1.86 atm1.86 atm. What mass of water was present in the container? The aqueous tension of water at 29 ∘C29 ∘C is 0.04 atm0.04 atm.
This is one of the steps of the solution given along with the question (edited to show the units):
Amount of substance of nitrogen:
n(NX2)=0.96 atm⋅3 L0.0821 atmLmol−1K−1⋅302 K=0.116 moln(NX2)=0.96 atm⋅3 L0.0821 atmLmol−1K−1⋅302 K=0.116 mol
Amount of substance of water:
n(HX2O)=0.04 atm⋅3 L0.0821 atmLmol−1K−1⋅302 K=0.00484 moln(HX2O)=0.04 atm⋅3 L0.0821 atmLmol−1K−1⋅302 K=0.00484 mol
The thing I don't understand here is that how can the volume of nitrogen and water be taken as 3 l3 l? Both of them would occupy some volume not the whole volume will not be occupied by one of them.
