Equilibrium constants Kc and KpEdexcel International A Level Chemistry: Mind map

Exam questions on Equilibrium constants Kc and Kp

1. In the Haber process nitrogen and hydrogen react reversibly: N₂(g) + 3H₂(g) ⇌ 2NH₃(g). A sealed vessel is held at 700 K until equilibrium is reached. The equilibrium concentrations are: N₂ 0.40 mol dm⁻³, H₂ 1.20 mol dm⁻³ and NH₃ 0.60 mol dm⁻³.
   Calculate the value of Kc at 700 K, including units.2 marks
2. Carbon dioxide reacts with hot carbon: C(s) + CO₂(g) ⇌ 2CO(g). Excess solid carbon is held in a closed vessel at 1000 K and the total pressure at equilibrium is 2.0 atm. The gas mixture at equilibrium contains 0.30 mol of CO₂ and 0.90 mol of CO.
   Calculate Kp at 1000 K, including units.2 marks
3. Dinitrogen tetraoxide dissociates in a sealed flask: N₂O₄(g) ⇌ 2NO₂(g). A student places 0.250 mol of N₂O₄ in a 5.00 dm³ flask at 373 K. At equilibrium 0.050 mol of N₂O₄ remains and the total pressure in the flask is 2.75 atm.
   Calculate Kc at 373 K, including units.3 marks