Discuss the relationship between equilibrium an... - SS1 Chemistry Energy Changes in Chemical Reactions Question

Equilibrium in a chemical reaction refers to a state where the forward and reverse reactions occur at equal rates, resulting in no net change in the concentrations of reactants and products over time. The position of equilibrium is determined by the Gibbs free energy (ΔG) of the system.

 

At equilibrium, the Gibbs free energy change (ΔG) is zero (ΔG = 0). This means that the system is at its lowest possible energy state and is in a state of dynamic balance. The relationship between ΔG and equilibrium is given by the following equation:

 

ΔG = ΔG° + RT ln(Q)

 

Where:

- ΔG is the change in Gibbs free energy

- ΔG° is the standard Gibbs free energy change

- R is the gas constant

- T is the temperature in Kelvin

- Q is the reaction quotient

 

If ΔG is negative (ΔG < 0), the reaction proceeds in the forward direction to reach equilibrium, favouring the formation of products. If ΔG is positive (ΔG > 0), the reaction proceeds in the reverse direction to reach equilibrium, favouring the formation of reactants. If ΔG is zero (ΔG = 0), the system is at equilibrium, and there is no net change in the concentrations of reactants and products.

 

The position of equilibrium is determined by the relative magnitudes of the forward and reverse Gibbs free energy changes. If the forward Gibbs free energy change is lower in magnitude than the reverse Gibbs free energy change (ΔGf < Gr), the equilibrium position will favour the reactants. Conversely, if the forward Gibbs free energy change is higher in magnitude than the reverse Gibbs free energy change (ΔGf > Gr), the equilibrium position will favour the products.