Final answer:
The equilibrium constant (Kp) for the reaction N₂(g) + 3H₂(g) = 2NH₃(g) is expressed as Kp = P(NH₃)² / (P(N₂) × (P(H₂))³), which varies with temperature.
Step-by-step explanation:
The equilibrium constant for the reaction N₂(g) + 3H₂(g) = 2NH₃(g) at a given temperature can be denoted as Kp or Kc depending on whether partial pressures or concentrations are used. While the numeric value of an equilibrium constant is dependent on the temperature, it is not dependent on the initial concentrations of reactants.
The equilibrium expression for Kp with respect to the given reaction is:
\[Kp = \frac{P(NH₃)^2}{P(N₂)(P(H₂))^3}\]
Where P represents the partial pressures of the gases involved. At 745 K, if given specific partial pressures, one can calculate the direction in which the reaction will shift to reach equilibrium.
Furthermore, changes in temperature lead to different values of the equilibrium constant, as shown with K25°C = 3.3 \times 108, K177°C = 2.6 \times 103, and K327°C = 4.1.