Gibbs Free Energy and Equilibrium Concepts

This video tutorial explores the relationship between Gibbs free energy and the equilibrium constant, emphasizing their dependence on temperature. It explains the conditions under which reactions are spontaneous or non-spontaneous, using graphs to illustrate these concepts. An example problem demonstrates how to calculate the equilibrium constant using standard free energies of formation. The video also delves into the temperature dependence of equilibrium constants, showing how to derive and interpret related equations.

What is the relationship between free energy and the equilibrium constant?

• Free energy is only relevant at non-standard conditions.

• Free energy is independent of the equilibrium constant.

• Free energy is always positive when the equilibrium constant is greater than one.

• Free energy is related to the equilibrium constant through the equation ΔG = -RT ln(K).

Under what condition is the Gibbs free energy of a reaction zero?

• When the equilibrium constant is less than one.

• When the reaction is at non-standard conditions.

• When the reaction is at equilibrium.

• When the temperature is above 298 K.

What does a large equilibrium constant (K > 1) indicate about a reaction?

• The reaction is at equilibrium.

• The reaction is spontaneous in the forward direction.

• The reaction has more reactants than products.

• The reaction is non-spontaneous in the forward direction.

What does a negative Gibbs free energy under standard conditions indicate?

• The reaction has more reactants than products.

• The reaction is non-spontaneous.

• The reaction is at equilibrium.

• The reaction is spontaneous.

What happens to the Gibbs free energy when K equals 1?

• It becomes positive.

• It becomes negative.

• It becomes zero.

• It becomes undefined.

In the example problem, what is the calculated equilibrium constant at 25°C?

• 3.09

• 2.80

• 0.50

• 1.00

How does the equilibrium constant change with temperature?

• It remains constant regardless of temperature changes.

• It changes depending on the reaction's enthalpy and entropy.

• It increases as temperature increases.

• It decreases as temperature increases.

What is the significance of the slope in the plot of ln(K) versus 1/T?

• It represents the enthalpy of the reaction divided by R.

• It represents the temperature of the reaction.

• It represents the entropy of the reaction.

• It represents the equilibrium constant.

What is the formula for calculating Gibbs free energy from enthalpy and entropy?

• ΔG = ΔH + TΔS

• ΔG = ΔH - TΔS

• ΔG = TΔS - ΔH

• ΔG = ΔH / TΔS

What does the y-intercept represent in the plot of ln(K) versus 1/T?

• The enthalpy of the reaction.

• The equilibrium constant.

• The temperature of the reaction.

• The entropy of the reaction divided by R.