The reaction below reaches equilibrium in a closed reaction vessel.Does the mass of Fe(s) increase, decrease or stay the same if the mixture is

The reaction below reaches equilibrium in a closed reaction vessel. Does the mass of Fe(s) increase, decrease or stay the same if the mixture is transferred to a smaller reaction vessel?

3 Fe(s) + 4 H2O(g)  ⇌ 

 Fe3O4(s) + 4 H2(g)  

The mass of Fe(s) :

 increases

 decreases

 stays the same