3.1.8.3 Entropy

• What does entropy measure in a system?

  Disorder or randomness
• The second law of thermodynamics implies that the entropy of the universe as a whole is continually increasing.


  True
• What does the Boltzmann entropy equation relate entropy to?

  Number of microstates
• How does temperature affect entropy?

  Increases entropy
• Higher temperatures increase entropy by providing more kinetic energy to molecules.


  True
• Melting ice increases entropy as water molecules gain freedom of movement.


  True
• What is the relationship between entropy and microstates?

  More microstates, higher entropy
• What happens to entropy in an isolated system at equilibrium according to the second law?

  It is maximized
• The Boltzmann entropy equation shows that entropy is directly proportional to the number of microstates.

  False
• Higher temperatures increase entropy by providing more kinetic energy to molecules.
• Order the phases of matter from lowest to highest entropy:

  1️⃣ Solid

  2️⃣ Liquid

  3️⃣ Gas
• Match the factor with its influence on entropy:

  Phase Changes ↔️ Solid < Liquid < Gas

  Temperature ↔️ Higher temperature increases entropy

  Complexity of Molecules ↔️ More complex molecules increase entropy

  Pressure ↔️ Lower pressure increases entropy
• An increase in entropy often favors spontaneous reactions because the products have more freedom and arrangements.
• A positive ΔS makes ΔG more negative, favoring spontaneity.
• A negative ΔG indicates a spontaneous reaction, while a positive ΔG indicates a non-spontaneous reaction.
• A negative $ΔG$ indicates a spontaneous reaction
• Dissolving salt in water is spontaneous because it has a negative ΔG
• Entropy is a measure of the disorder or randomness of a system
• What happens to entropy at equilibrium in an isolated system according to the second law of thermodynamics?

  Maximized at equilibrium
• The Boltzmann entropy equation is given by $S =$$k_{B} \ln \Omega$, where k_B is the Boltzmann constant
• Higher temperatures increase entropy by providing more kinetic energy
• What happens to entropy under high pressure conditions?

  Reduces
• Higher temperature increases entropy
• Arrange the phases of matter in order of increasing entropy.

  1️⃣ Solid

  2️⃣ Liquid

  3️⃣ Gas
• Higher temperatures provide more kinetic energy to molecules.
• What does a positive entropy change in a chemical reaction often favor?

  Spontaneous reactions
• What conditions are required for the reaction $N_{2}(g) +$$3H_{2}(g) → 2NH_{3}(g)$ to be spontaneous?


  Low temperature, high pressure
• A positive Gibbs free energy (ΔG) requires energy input to make the reaction occur.


  True
• A negative ΔS in a reaction indicates that disorder decreases, favoring the reactants.


  True
• What does the second law of thermodynamics state about entropy in an isolated system not in equilibrium?

  Entropy increases over time
• The second law of thermodynamics states that the entropy of an isolated system not in equilibrium will tend to increase over time
• Arrange the phases of matter in order of increasing entropy:

  1️⃣ Solid

  2️⃣ Liquid

  3️⃣ Gas
• Which phase of matter has the lowest entropy due to its highly ordered structure?

  Solid
• How does lower pressure influence entropy?

  Increases it
• Arrange the following processes in order of increasing entropy:

  1️⃣ Freezing water

  2️⃣ Melting ice

  3️⃣ Heating a gas
• Match the entropy level with the number of microstates:

  High Entropy ↔️ Many possible arrangements

  Low Entropy ↔️ Few possible arrangements
• The second law of thermodynamics describes the spontaneous tendency of systems to become more disordered
• The Boltzmann entropy equation is S = k_{B} \ln \Omega</latex>, where $k_{B}$ is the Boltzmann constant
• Entropy generally increases as a substance transitions from solid to liquid
• More complex molecules tend to have higher entropy due to the greater number of possible arrangements for their constituent atoms.