Chapter 6 Flashcards
(15 cards)
Define dynamic equilibrium.
Forward and reverse reactions occur at the same rate, with no net change in concentrations.
State Le Chatelier’s Principle.
When a system at equilibrium is disturbed, it shifts to counteract the change.
How does increasing concentration of reactants affect equilibrium?
Equilibrium shifts right to form more products.
How does increasing temperature affect exothermic equilibrium?
Equilibrium shifts left to absorb heat (favor reactants).
How does increasing pressure affect equilibrium involving gases?
Equilibrium shifts toward side with fewer moles of gas.
What is the equilibrium constant Kc?
Ratio of product concentrations to reactant concentrations, each raised to their stoichiometric powers at equilibrium.
Write the expression for Kc for aA + bB ⇌ cC + dD.
Kc = [C]^c × [D]^d ÷ [A]^a × [B]^b.
What does a large Kc value mean?
Equilibrium lies to the right; products predominate.
What does a small Kc value mean?
Equilibrium lies to the left; reactants predominate.
Does changing concentration affect Kc?
No, Kc remains constant at a given temperature.
Does changing pressure affect Kc?
No, Kc remains constant at a given temperature.
Does changing temperature affect Kc?
Yes, Kc changes because equilibrium position shifts.
Explain the Haber process in terms of equilibrium and conditions.
N₂ + 3H₂ ⇌ 2NH₃, exothermic; high pressure and moderate temperature with iron catalyst favours ammonia formation.
Why is compromise temperature used in Haber process?
Low temp favours yield but is slow; high temp increases rate but lowers yield.
What happens to equilibrium if a catalyst is added?
Equilibrium position stays the same but is reached faster.
