Equilibrium

Question 1

When is equilibrium reached?

Answer 1

When the apparatus prevents the escape of reactants and products and the forward and reverse reactions occur at exactly the same rate.

Question 2

What happens if a system is at equilibrium and a change is made to any of the conditions

counteract the change

Answer 2

The system responds to counteract the change.

Question 3

Describe the effect of changing the concentration of reactant and product on the position of equilibrium

Answer 3

The system is no longer at equilibrium and the concentrations of all the substances will change until equilibrium is reached again.

Question 4

Describe the effect of changing temperature on the position of the equilibrium

Answer 4

If the temperature of a system at equilibrium is increased:
The amounts of products at equilibrium increases for an endothermic reaction

The amounts of products at equilibrium decreases for an exothermic reaction

Question 5

What happens If the temperature of a system at equilibrium is decreased

Answer 5

• the amount of products at equilibrium decreases for an endothermic reaction
• the amount of products at equilibrium increases for an exothermic reaction.

Question 6

Describe the effect of changing pressure on the position of the equilibrium

Answer 6

Only applies to equilibria that involves gases:
Increase in pressure causes the equilibrium position to shift towards the side with the smaller number of molecules and vice a versa

It has no effect on the reaction where the number of gas molecules are equal on both sides of the equations

Question 7

What happens If the concentration of a reactant is increased

m

Answer 7

more products will be formed until equilibrium is reached again.

Question 8

What happens if the concentration of a product is decreased

Answer 8

more reactants will react until equilibrium is reached again.

Question 9

What happens when there is a decrease in pressure in equilibrium?

the equilibrium positions

Answer 9

The equilibrium position shifts towards the side with the larger number of molecules

Question 10

Describe the effect of a catalyst on the position of the equilibrium

Answer 10

No effect
It just speeds up both forward and backward reactions equally
i.e equilibrium is achieved faster