Topic 10 - Introduction to Equilibria Flashcards
Definition of dynamic equilibrium
A reaction which proceeds in both the forwards and reverse directions at the same time
What occurs at equilibrium
- the concentration of reactants and products remains constant because
- the rate of the forward reaction is equal to the rate of the reverse reaction
Definition of Le Chatelier’s Principle
a system at equilibrium will shift or move to oppose any change imposed upon it
What are compromise conditions?
Conditions chosen to reach highest yeild
They are a trade off between yield of product and other considerations, such as rate of reaction cost and safety.
How does increasing concentration effect the position of equilibria?
Increasing concentration of the reactant will shift the position of equilibria to the right in order to get rid of the extra reactant. It does this by making more product.
If you increase the concentration of the product the position of equilibrium moves the left.
How does increasing the pressure effect the position of equilibrium?
Increasing the pressure shifts the equilibrium to the side with fewer gas molecules to oppose the increase in pressure.
How does increasing the temperature affect the position of equilibria?
Increasing the temperature favours the endothermic reaction (+ve) shifting the position of equilibrium either forwards or backwards to oppose the increase in temperature.
Effect of adding a catalyst
Catalyst does not change the position of equilibrium because it increases the rate of the forwards and backwards reaction by the same amount.
Law of chemical equilibrium
Direction taken by a reaction is dependent not only on the mass of the various components of the reaction, but also upon the concentration.
Writing Kc expressions
aA + bB cC + dD
Kc = [C]^c[D]^d
—————–
[A]^a[B]^b
