Question

At 50.0∘C, the process X+Y⟶Z has a standard free energy change of 45.0kJmol. What is the free energy change (in kilojoules per mole) at the same temperature when with [X]=0.15 M, [Y]=0.46 M, and [Z]=0.33 M?

Answer 1

The non-standard free energy change of the reaction X + Y ⇌ Z at 50.0°C can be calculated using the equation ΔG = ΔG° + RT ln Q, substituting the given values for concentrations and temperature.

Step-by-step explanation:

The free energy change of the reaction X + Y ⇌ Z at 50.0°C (or 323.15 K) with concentrations [X]=0.15 M, [Y]=0.46 M, and [Z]=0.33 M can be calculated using the equation ΔG = ΔG° + RT ln Q, where Q is the reaction quotient and R is the gas constant (8.314 J/mol·K).

Firstly, calculate the reaction quotient Q = [Z] / ([X][Y]) = 0.33 / (0.15×0.46). Then, substitute values into the equation:

ΔG = 45.0 kJ/mol + (8.314 × 10⁻³ kJ/(mol·K) × 323.15 K) ln Q

After calculating the ln Q, we can determine the non-standard free energy change at the given temperature and concentrations.

The standard free energy change (not to be confused with the non-standard free energy change which depends on the concentration of reactants and products) is a measure of the spontaneity of a reaction under standard conditions and is denoted as ΔG°. It can be calculated as ΔG° = ΔH° - TΔS°, as seen in the provided reference information.