Thermodynamics: Gibbs Energy and Equilibrium

The video tutorial explains equation 15.4, a fundamental thermodynamics equation linking the equilibrium constant (K) to the standard Gibbs energy change (Delta G). It highlights the use of the natural logarithm of K and the significance of the negative sign in the equation. The derivation process is outlined, showing how Gibbs energy concepts are applied. Finally, the equation's application at equilibrium is discussed, emphasizing that at equilibrium, Delta G is zero and the ratio of product to reactant activities equals K.

What does Equation 15.4 in thermodynamics link together?

• Standard Gibbs energy change and temperature

• Equilibrium constant and standard Gibbs energy change

• Equilibrium constant and enthalpy change

• Enthalpy change and temperature

What is the significance of Equation 15.4 in thermodynamics?

• It links the equilibrium constant to the standard Gibbs energy change

• It determines the pressure of a reaction

• It predicts the temperature of a reaction

• It calculates the volume of a reaction

What does a large positive value of K indicate about ΔG standard?

• ΔG standard is negative

• ΔG standard is undefined

• ΔG standard is positive

• ΔG standard is zero

What does the natural logarithm of K in the equation signify?

• It indicates the reaction is endothermic

• It relates to the spontaneity of the reaction

• It is unrelated to the reaction

• It shows the reaction is exothermic

What is the role of the negative sign in the equation relating K and ΔG?

• It indicates a direct relationship

• It shows an inverse relationship

• It has no significance

• It indicates a proportional relationship

In the derivation of the equation, what is the simplest reaction model considered?

• One mole of reactant produces one mole of product

• One mole of reactant produces two moles of product

• Two moles of reactant produce two moles of product

• Two moles of reactant produce one mole of product

What is the expression for Gibbs energy of any substance according to Chapter 14?

• Standard Gibbs energy minus RT logarithm of activity

• Standard Gibbs energy divided by RT logarithm of activity

• Standard Gibbs energy plus RT logarithm of activity

• Standard Gibbs energy times RT logarithm of activity

What is the activity of a gas defined as in the derivation?

• Partial pressure divided by standard pressure

• Concentration of the gas

• Concentration divided by standard concentration

• Partial pressure of the gas

At equilibrium, what is the value of ΔG for a reaction?

• ΔG is positive

• ΔG is negative

• ΔG is zero

• ΔG is undefined

What happens to the expression for ΔG when a reaction reaches equilibrium?

• It becomes undefined

• It equals the equilibrium constant

• It equals the standard Gibbs energy

• It equals zero