13.4.1 Gibbs Free Energy Equation

• Gibbs Free Energy determines the spontaneity of a chemical reaction at constant temperature and pressure
• What is the Gibbs Free Energy equation?

  $G =$$H - TS$
• Enthalpy measures the heat energy exchanged in a reaction.
• Temperature in the Gibbs Free Energy equation must be in Kelvin
• What does entropy measure?

  Disorder or randomness
• A negative ΔG indicates a spontaneous reaction.
• Match the component with its description:

  Enthalpy ↔️ Heat exchanged at constant pressure

  Entropy ↔️ Measure of disorder

  Temperature ↔️ Temperature in Kelvin
• Enthalpy is the heat content of a system at constant pressure
• What is the unit of entropy?

  J/(mol·K)
• Entropy measures the degree of energy dispersal in a system.
• Order the variables in the Gibbs Free Energy equation:

  1️⃣ $G$ (Gibbs Free Energy)

  2️⃣ $H$ (Enthalpy)

  3️⃣ $T$ (Temperature)

  4️⃣ $S$ (Entropy)
• A positive value of $G$ indicates a non-spontaneous reaction.
• What is the unit of enthalpy?

  kJ/mol
• Entropy measures the disorder or randomness within a system.
• What is the unit of entropy?

  J/(mol·K)
• A negative value of Gibbs Free Energy indicates a spontaneous reaction.
• What does the symbol $G$ represent in the Gibbs Free Energy equation?


  Gibbs Free Energy
• What unit is temperature measured in for the Gibbs Free Energy equation?

  Kelvin
• A positive value of Gibbs Free Energy indicates a non-spontaneous reaction.
• Arrange the components of the Gibbs Free Energy equation by their associated variables:

  1️⃣ $G$ - Gibbs Free Energy

  2️⃣ $H$ - Enthalpy

  3️⃣ $T$ - Temperature

  4️⃣ $S$ - Entropy
• What is enthalpy defined as?

  Heat content at constant pressure
• Entropy is measured in units of J/(mol·K)
• Gibbs Free Energy is a measure of spontaneity.
• What does the variable $H$ represent in the Gibbs Free Energy equation?


  Enthalpy
• In the Gibbs Free Energy equation, temperature is measured in Kelvin
• What does $G$ represent in the Gibbs Free Energy equation?


  Gibbs Free Energy
• $H$ in the Gibbs Free Energy equation stands for Enthalpy
• What is the unit for temperature in the Gibbs Free Energy equation?

  Kelvin
• $S$ in the Gibbs Free Energy equation measures the disorder or randomness of a system.
• The unit for Gibbs Free Energy is kJ/mol
• Match the variable with its symbol and unit:

  Gibbs Free Energy ↔️ $G$, kJ/mol

  Enthalpy ↔️ $H$, kJ/mol
• What does the Gibbs Free Energy equation help determine?

  Spontaneity of a reaction
• The Gibbs Free Energy is measured in kJ/mol.
• In which unit is temperature measured in the Gibbs Free Energy equation?

  Kelvin
• $S$ in the Gibbs Free Energy equation represents the Entropy
• Order the conditions of spontaneity based on the value of $ΔG$:


  1️⃣ $ΔG < 0$ (Spontaneous)

  2️⃣ $ΔG =$$0$ (Equilibrium)

  3️⃣ $ΔG > 0$ (Non-spontaneous)
• If $ΔG < 0$, the reaction is spontaneous.
• What does it mean if $ΔG =$$0$?


  The system is at equilibrium
• If $ΔG > 0$, the reaction is non-spontaneous
• What does Gibbs Free Energy determine?

  Spontaneity of a reaction