9.5 Free Energy of Dissolution

• What is the equation relating free energy, enthalpy, entropy, and temperature?

  $\Delta G =$$\Delta H - T\Delta S$
• The magnitude of $\Delta G$ determines whether the dissolution process is spontaneous.


  True
• A negative \Delta G</latex> indicates that dissolution is spontaneous and favorable.

  True
• The relationship between free energy, enthalpy, and entropy is given by the equation $ΔG =$$ΔH - TΔS$, where T is the absolute temperature
• Arrange the factors affecting free energy of dissolution in terms of their effect.

  1️⃣ Exothermic enthalpy change (ΔH < 0)

  2️⃣ Increase in disorder (ΔS > 0)

  3️⃣ Endothermic enthalpy change (ΔH > 0)

  4️⃣ Decrease in disorder (ΔS < 0)
• A negative ΔG indicates that the dissolution process is thermodynamically favorable
• Calculate the Gibbs free energy change (ΔG) for dissolution if ΔH = -25 kJ/mol, ΔS = 50 J/mol·K, and T = 298 K.

  -39.9 kJ/mol
• A positive ΔG occurs when entropy decreases and/or enthalpy increases.


  True
• An exothermic dissolution process has a favorable enthalpy change on the free energy of dissolution.


  True
• What happens to the free energy of dissolution if the entropy change is negative?

  Becomes less favorable
• What is the significance of $\Delta G$ in dissolution?


  Determines spontaneity
• An increase in disorder during dissolution is favorable for entropy change (ΔS > 0).


  True
• An endothermic enthalpy change (ΔH > 0) is favorable for free energy of dissolution.

  False
• A positive ΔG indicates that the dissolution process is spontaneous.

  False
• In the Gibbs free energy equation, $T$ represents the absolute temperature in Kelvin
• What does a negative ΔG indicate about the dissolution process?

  Spontaneous and favorable
• What is the free energy of dissolution?

  Change in Gibbs free energy
• An increase in disorder during dissolution has a favorable effect on the free energy of dissolution.


  True
• If the dissolution process is exothermic, the enthalpy change \Delta H</latex> is negative
• What type of enthalpy change is favorable for dissolution?

  Exothermic (ΔH < 0)
• What is the definition of free energy of dissolution?

  Change in Gibbs free energy
• How does temperature influence Gibbs free energy change (ΔG)?

  Amplifies entropy changes
• What is the formula for calculating the Gibbs free energy change (ΔG)?

  $ΔG =$$ΔH - TΔS$
• Ensuring enthalpy and entropy have consistent units is crucial for calculating ΔG.


  True
• The magnitude of ΔG indicates the extent of spontaneity, with a more negative ΔG indicating a more favorable