Topic 10: Equilibrium I

Question 1

Explain the dynamic equilibrium

Answer 1

• The rate of the forward reaction is equal to the rate of the backwards reaction
• The concentrations of reactants and products remain constant

Question 2

What is a homogeneous system

Answer 2

When all reactants and products are in the same phase

Question 3

What is a heterogeneous system

Answer 3

When the reactants and products are in at least 2 different phases
Only gaseous and aqueous species are included in the Kc expression

Question 4

What is the equilibrium constant?

Answer 4

Kc
It uses the concentrations of reactants and products at equilibrium

Question 4

What is the reactant quotient?

Answer 4

Q
- This is the mathematical relationship between the concentrations of reactants and products in a reaction
- It can be determined at any point during a reaction

Question 5

When writing Kc expressions, what key points must you remember?

Answer 5

Products / Reactants
Use [Square] brackets

Question 6

How do you complete a Kc calculation?

Answer 6

1. Make an ICE table
2. Find the Equilibrium moles
3. Divide this by the total volume
4. Use this (equilibrium concentrations) and put them into the Kc expression

Question 7

What do Kc values tell us?

Answer 7

Kc > 1 : position of equilibrium lies to the left
Kc < 1 : position of equilibrium lies to the right