How far

• 2NO + O2 -> 2NO2

  At 298K Kp = 2.19 x 10^12

  At 1000K Kp = 2.03 x 10^-1

  The chemist increases the pressure of the equilibrium mixture at the same temperature. State and explain in terms of Kp how you would expect the equilibrium position to change

  Equilibrium shifts to right

  Ratio in Kp decreases

  Equilibrium shift cause the ratio to increase to restore Kp
• mole fraction

  The ratio of the moles of 1 gas to the total number of moles of all gases
• partial pressure

  the contribution that each gas makes towards the total pressure
• N2(g) + 3H2(g) ⇌ 2NH3(g) ΔH = −92 kJ mol−1 Equation 1

  What effect will increasing the temperature have on the composition of the equilibrium mixture

  and on the value of the equilibrium constant?

  The forward reaction is exothermic, so an increase in temperature favours the backward reaction

  therefore there will be more N2 and H2 AND therefore the value of the equilibrium constant will decrease
• How does a catalyst affect equilibrium constants

  affects rate of reaction but not the position of equilibrium position

  speeds up both the forward and backward reaction in the equilibrium by the same factor
• homogeneous equilibrium

  all the reactants and products are in the same physical state
• heterogeneous equilibrium

  when the reactants and products are present in more than one physical state

  • only gases present in Kp equation
• what does K=1 indicate?

  equilibrium half way between products and reactants
• what doesn't affect the value of K

  concentration, pressure or the presence of a catalyst
• K>1

  shift to product
• K<1

  shift to reactants
• affect on Kp when pressure is increased and there is a higher conc on the bottom of the ratio

  ratio is less than Kp
• affect on Kp when pressure is increased and there is a higher conc on the top of the ratio

  ratio is more than Kp
• what happens to the ratio of products to reactants when Kc decreases

  products decrease and reactants decrease
• what happens to the ratio of products to reactants when Kc increases

  products increase and reactants decrease