U2.3: How Far?

Question 1

Define closed system

Answer 1

No matter can escape however energy can

Question 2

Define Dynamic Equilibrium

Answer 2

When the rate of the forward reaction is equal to the rate of backward reaction in a closed system

Question 3

State the 5 features of an equilibrium state and explain them

Answer 3

Eq is dynamic:
- Reaction stops but forward and backward reaction occurs at the same rate

Eq is achieved in a closed system:
- Closed system prevents exchange of matter

Conc of reactants and products is constant:
- Being produced and destroyed at equal rates

No change in macroscopic properties (colour, ph, density):
- These depend on concentrations

Eq can be reached from any direction:
- Reaction can start with all reactants, products, mixtures

Question 4

State what Kc is and its formula

Answer 4

Kc is a constant for a reaction at a specific temperature (temperature dependent) and gives an idea of how far a reaction proceeds

• Formula: Order of products / Order of Reactants

Question 5

State each of the 3 magnitudes of Kc and the extent of the reaction

Answer 5

Kc > 1:
- Eq favours the forward reaction (R<P)

Kc=1:
- Eq is in dynamic equilibrium (R=P)

Kc < 1:
- Eq favours the backward reaction (R>P)