9.2 Gibbs Free Energy and Thermodynamic Favorability

• What does Gibbs Free Energy (ΔG) measure at constant temperature and pressure?

  Maximum reversible work
• What units must absolute temperature be in for the Gibbs Free Energy equation?

  Kelvin
• What does ΔH represent in the Gibbs Free Energy equation?

  Enthalpy change
• Under what temperature conditions is a reaction spontaneous if ΔH < 0 and ΔS < 0?

  Low temperature
• What is represented by ΔH in the Gibbs Free Energy equation?

  Enthalpy change
• When ΔH is negative and ΔS is negative, the reaction is spontaneous at high temperatures

  False
• A reaction with ΔG > 0 requires external energy to proceed


  True
• What does ΔG represent in the Gibbs Free Energy equation?

  Gibbs Free Energy change
• What does ΔS represent in the Gibbs Free Energy equation?

  Entropy change
• What does a positive ΔG indicate about a reaction?

  Non-spontaneous
• Enthalpy (ΔH) measures heat absorbed or released during a chemical reaction
• Entropy (ΔS) is the measure of disorder or randomness in a system.
• In the Gibbs Free Energy equation, ΔH represents the enthalpy change of the system.
• What does the enthalpy change (ΔH) measure in thermodynamics?

  Heat absorbed or released
• A reaction with ΔG < 0 is always spontaneous


  True
• The Gibbs Free Energy measures the maximum reversible work a system can perform at constant temperature and volume

  False
• A reaction with ΔG > 0 requires external energy to proceed


  True
• What does a negative ΔH indicate in a chemical reaction?

  Exothermic reaction
• What is the term for the heat absorbed or released during a chemical reaction?

  Enthalpy
• If ΔG < 0, the reaction is always non-spontaneous

  False
• ΔH represents the enthalpy change of a reaction.


  True
• Order the conditions based on their spontaneity for ΔG values:

  1️⃣ ΔG < 0: Spontaneous reaction

  2️⃣ ΔG > 0: Non-spontaneous reaction

  3️⃣ ΔG = 0: Reaction at equilibrium
• Match the conditions with their spontaneity at different temperatures:

  ΔH < 0, ΔS < 0 ↔️ Spontaneous at low T

  ΔH > 0, ΔS > 0 ↔️ Spontaneous at high T
• When ΔH is negative and ΔS is negative, the reaction is spontaneous at low temperatures
• Gibbs Free Energy combines enthalpy and entropy to determine reaction spontaneity
• A reaction with ΔG < 0 is spontaneous

  True
• When both ΔH and ΔS are negative, a reaction is spontaneous at low temperatures.
• The Gibbs Free Energy equation is ΔG = ΔH - TΔS, where ΔS represents the entropy change of the system.
• Match the conditions with the resulting spontaneity:

  ΔH < 0, ΔS > 0 ↔️ Always spontaneous

  ΔH > 0, ΔS < 0 ↔️ Always non-spontaneous
• In the Gibbs Free Energy equation, T is measured in Celsius.

  False
• In the Gibbs Free Energy equation, T is the absolute temperature measured in Kelvin
• A reaction is at equilibrium when ΔG equals zero.
• A positive ΔS indicates an increase in disorder within the system.

  True
• Which type of reaction releases heat to the surroundings?

  Exothermic
• A reaction with a ΔG greater than zero is non-spontaneous.


  True
• The Gibbs Free Energy equation is ΔG
• A reaction is at equilibrium when ΔG is equal to zero
• Match the conditions with their corresponding spontaneity:

  ΔH < 0, ΔS > 0 ↔️ Always spontaneous

  ΔH > 0, ΔS < 0 ↔️ Always non-spontaneous

  ΔH < 0, ΔS < 0 ↔️ Spontaneous at low T

  ΔH > 0, ΔS > 0 ↔️ Spontaneous at high T
• In the Gibbs Free Energy equation, the absolute temperature must be in Kelvin
• A positive ΔS indicates an increase in disorder