Chemistry CCEA AS Level 2.10 (Equilibrium)

What is a reversible reaction?

A reaction which can go both forwards and backwards

What is a closed system?

A system from which nothing can escape or be added

What is dynamic equilibrium?

A reaction in which the rate of the forward reaction is equal to the rate of the backwards reaction

What is an equilibrium?

A reversible reaction in which the amounts of each reactant/produce remains constant

What is a homogeneous equilibrium?

A reaction in which all reactants and products are in the same physical state

What is a heterogeneous equilibrium?

A reaction in which all reactants and products are not in the same physical state

How can the position of equilibrium be altered?

Changing of the concentration of the reactants or products/changing the pressure (in reactions involving gases)/Changing the temperature

What is the name of the principle which summarises the affect of factors on position of equilibrium?

Le Chatelier's principle

What does Le Chatelier's Principle state?

If a change is made to an equilibrium reaction the equilibrium will move in the direction to minimise change

What effect will increasing the concentration of a reactant have on equilibrium?

The equilibrium will move to oppose the change

What do catalysts do to equilibrium?

They alter the rate at which equilibrium is achieved but will not alter the position of the equilibrium

What does the equilibrium law state?

Kc = [C]^c[D]^d/[A]^a[B]^b

What does a large Kc value indicate?

The equilibrium lies to the RHS

What does a small Kc value indicate?

The equilibrium lies to the LHS

What can change the Kc value?

Temperature