13147 15 At very high temperatures, in a closed system, nitrogen can be oxidised to form nitrogen(II) oxide in a reversible reaction: N2(g) + O2(g) ⇌ 2NO(g)      ∆H = +180 kJ A position of dynamic equilibrium is established and the equilibrium is described as homogeneous. (a) Define the term homogeneous. [1] (b) (i) Deduce an expression and corresponding units for the equilibrium constant, Kc, for this reaction. [2] (ii) What is the significance of a small value of Kc? [1] 13147 [Turn over (c) Explain the effect of increasing the pressure on the equilibrium yield of nitrogen(II) oxide. [2] (d) Explain the effect of increasing the temperature on the equilibrium yield of nitrogen(II) oxide. [3]