Question 1
Paper 2Hard9 marksIn a sealed, fixed-volume vessel, nitrogen and oxygen form nitrogen monoxide at 1500 K:
N₂(g) + O₂(g) ⇌ 2NO(g)
At this temperature, Kc = 4.00 × 10⁻⁶. At a particular instant, the concentrations are [N₂] = 0.0500 mol dm⁻³, [O₂] = 0.0400 mol dm⁻³ and [NO] = 1.00 × 10⁻⁵ mol dm⁻³.
(a)[2]
Calculate Qc for this mixture and predict the direction in which the reaction will proceed to reach equilibrium.
(b)[4]
Determine the equilibrium concentrations of the three gases. Show how you check that any approximation used is justified.
(c)[3]
After the mixture reaches equilibrium, an injection increases [NO] by 2.00 × 10⁻⁴ mol dm⁻³. Immediately after the injection, before further reaction occurs, calculate Qc and predict the direction in which the reaction will proceed.