📚 Topic Summary
Gibbs Free Energy ($G$) is a thermodynamic potential that measures the amount of energy available in a chemical or physical system to do useful work at a constant temperature and pressure. The change in Gibbs Free Energy ($\Delta G$) predicts the spontaneity of a reaction. A negative $\Delta G$ indicates a spontaneous reaction, a positive $\Delta G$ indicates a non-spontaneous reaction, and a $\Delta G$ of zero indicates that the reaction is at equilibrium.
The Gibbs Free Energy change is calculated using the following equation: $\Delta G = \Delta H - T\Delta S$, where $\Delta H$ is the change in enthalpy, $T$ is the absolute temperature (in Kelvin), and $\Delta S$ is the change in entropy.
🧪 Part A: Vocabulary
Match each term with its correct definition:
| Term |
Definition |
| 1. Gibbs Free Energy |
A. A measure of the disorder or randomness of a system. |
| 2. Enthalpy |
B. A state where the rates of forward and reverse reactions are equal. |
| 3. Entropy |
C. The heat content of a system at constant pressure. |
| 4. Spontaneous Process |
D. A thermodynamic potential that measures the energy available to do useful work. |
| 5. Equilibrium |
E. A process that occurs without external intervention. |
(Answers: 1-D, 2-C, 3-A, 4-E, 5-B)
🌡️ Part B: Fill in the Blanks
The Gibbs Free Energy change ($\Delta G$) is a crucial concept in thermodynamics. It helps predict whether a reaction will occur ____________. The equation to calculate $\Delta G$ is $\Delta G = \Delta H - T\Delta S$, where $\Delta H$ represents the change in __________, $T$ is the __________ in Kelvin, and $\Delta S$ is the change in __________. A __________ $\Delta G$ indicates a spontaneous reaction.
(Answers: spontaneously, enthalpy, temperature, entropy, negative)
🤔 Part C: Critical Thinking
Explain how the Gibbs Free Energy equation ($\Delta G = \Delta H - T\Delta S$) can be used to determine the temperature at which a reaction becomes spontaneous, assuming $\Delta H$ and $\Delta S$ do not change significantly with temperature.