(4.6.2)(Reversible reactions and dynamic equilibrium)

What are reversible reactions?

Reactions where the products can react backwards to form the reactants.

How can you change the direction of a reversible reaction?

Changing the conditions (e.g temperature).

If a reaction is exothermic forward what does this mean about the backwards reaction?

It would be the opposite so it would be endothermic.

What is one condition that is needed to reach equilibrium?

An apparatus that prevents the escape of reactants and products.

What is equilibrium?

Equilibrium is when the forward and backwards reactions occur at exactly the same rate.

What is Le Chatelier’s principle?

If a system is at equilibrium and a change is made to any of the conditions, then the system responds to counteract the change.

What happens if the concentration of reactants is increased?

More product will be formed.

What happens if the concentration of the product is decreased?

More reactants will react.

What happens if the temperature of a system at equilibrium is increased?

The equilibrium will move in the endothermic direction to try and decrease it. You will get more products for the endothermic reaction and fewer for the exothermic.

What happens if the temperature of a system at equilibrium is decreased?

The equilibrium will move in the exothermic direction to try and increase it. You will get more products for the exothermic reaction and fewer for the endothermic.

What happens if pressure is increased in a gaseous reaction?

An increase in pressure causes the equilibrium position to shift towards the side with the smaller number of molecules as shown by the symbol equation for that reaction.

What happens if pressure is decreased in a gaseous reaction?

A decrease in pressure causes the equilibrium position to shift towards the side with the larger number of molecules as shown by the symbol equation for that reaction.