The reaction N2O₄ → 2 NO₂ is allowed to reach equilibrium in chloroform solution at 25 °C. The equilibrium concentrations are 0.405 mol · L^–1 N₂O₄ and 2.13 mol · L^–1 NO₂. 

(a) Calculate K for the reaction. 

(b) An additional 1.00 mol NO₂ is added to 1.00 L of the solution and the system is allowed to reach equilibrium again at the same temperature. Use Le Chatelier’s principle to predict the direction of change (increase, decrease, or no change) for N₂O₄, NO₂, and K after the addition of NO₂. 

(c) Calculate the final equilibrium concentrations after the addition of NO₂ and confirm that your predictions in part (b) were valid. If they do not agree, check your procedure and repeat it if necessary.