Kp ( year 13) topic

what is homogenous equilibria

equilibria where all species are in the same state

heterogenous equilibria

equilibria where the species are in different states

equation for the mole fraction of a gas (Xa)

Xa (mole fraction for A) = number of moles of Gas A/ total numner of moles of gas

what is the partial pressure of a gas in a mixture

the pressure which one of the gases would exert if it occupied the whole container

equation for the partial pressure of gas A

p(A) = total pressure x mole fraction

what does the total pressure of a mixture of gases equal

the sum of the partial pressures

what is the expression for Kp

Kp = partial pressures of products / partial pressures of reactants

Explain how does an increase in temperature affect the constants Kc and Kp

Increase temp, equilibrium moves in endothermic direction to the left. Therefore the p(products) gets smaller and the p(reactants) gets larger. As Kp = p(products) / p(reactants), Kp will decrease. Kc will also decrease

Explain how an increase in pressure affects Kc and Kp

If the pressure increase then equilibrium will move to the left to the side with fewer moles of gas. The partial pressures of both R + P increase proportionally so that p(products)/p(reactants) stays the same and Kp does not change. Kc does also not change. Changing the pressure only effects reactions involving gases

What happens to Kc if the concentration of a reactant is increased and explain why

If the concentration of a reactant is increased then equilibrium moves right to remove added reactant. Kc does not change.This is because Kc = [products]/[reactants] and the conc of P/R increase proportionally to keep Kc constant. Eqm moves to reestablish Kc/Kp

Describe and explain the effect on Kc and Kp if a catalyst is used

Catalysts affect the rate of a reaction but not the position. They will affect how quickly equilibrium is reached so there is no change on Kc or Kp - the equilibrium position does not change.