(a) When solid NaHCO₃ was placed in a rigid container of volume 2.50 L and heated to 160.°C, the equilibrium 2 NaHCO₃(s) ⇌ Na₂CO₃(s) + CO₂(g) + H₂O(g) was reached. At equilibrium, some of the starting material remains and the total pressure in the container is 7.68 bar. What is the value of K? 

(b) The reaction is repeated, but this time the container initially contains not only the solid reactant but also CO₂, with a partial pressure of 1.00 bar. What are the equilibrium concentrations of CO₂ and H₂O for the new experiment?