The reaction below reaches equilibrium in a closed reaction vessel. The enthalpy change for the forward reaction is +135 kJ/mol. Does the mass of Na 2 CO 3 increase, decrease or stay the same if the mixture is transferred to a smaller reaction vessel?
2 NaHCO 3 (s) --> Na 2 CO 3 (s) + CO 2 (g) + H 2 O(g)