Nitrogen oxides participate in a variety of atmospheric and industrial equilibria
CHEMISTRY · Multi-part · A Level · Chemistry · Chemical equilibria (Le Chatelier’s principle and Kc) · Chemical equilibria (Le Chatelier’s principle and Kc)
Problem
Nitrogen oxides participate in a variety of atmospheric and industrial equilibria. At 298 K, the following two reactions have the listed equilibrium constants:
Reaction (1): NO(g) + ½ O₂(g) ⇌ NO₂(g) K₁ = 1.2 × 10³
Reaction (2): 2 NO₂(g) ⇌ N₂O₄(g) K₂ = 6.3
Using only these data, address the questions below.
(a) Derive the balanced chemical equation for the overall process that converts nitric oxide into dinitrogen tetroxide without forming any other net products. Show how the two given elementary equilibria can be combined to obtain the overall equation.
(b) Calculate the numerical value of the equilibrium constant, K_overall, for the reaction obtained in part (a). Give your answer with the appropriate number of significant figures.
(c) Explain, in qualitative terms, what the magnitude of K_overall implies about the relative concentrations of reactants and products once equilibrium is reached under standard‐state conditions at 298 K.