📚 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. It combines enthalpy ($H$) and entropy ($S$) to determine the spontaneity of a reaction. A negative value of $\Delta G$ indicates a spontaneous reaction, while a positive value indicates a non-spontaneous reaction. When $\Delta G$ is zero, the reaction is at equilibrium.
The change in Gibbs Free Energy ($\Delta G$) can be 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. Understanding how to calculate and interpret $\Delta G$ is crucial for predicting the feasibility of chemical reactions.
🧮 Part A: Vocabulary
Match the 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 rate of forward and reverse reactions are equal. |
| 3. Entropy |
C. The heat content of a system at constant pressure. |
| 4. Spontaneous Process |
D. A process that occurs without external energy input. |
| 5. Equilibrium |
E. A thermodynamic potential that measures the energy available to do useful work. |
Matching Answers: 1-E, 2-C, 3-A, 4-D, 5-B
✍️ Part B: Fill in the Blanks
Complete the following paragraph with the correct terms related to Gibbs Free Energy:
The change in _______ _______ _______ ($\Delta G$) determines the _______ of a reaction. A _______ $\Delta G$ indicates a spontaneous reaction, while a _______ $\Delta G$ indicates a non-spontaneous reaction. The equation to calculate $\Delta G$ is $\Delta G = \Delta H - T\Delta S$, where $\Delta H$ is the change in _______, $T$ is the _______ in Kelvin, and $\Delta S$ is the change in _______. When $\Delta G$ is zero, the reaction is at _______.
Fill-in Answers: Gibbs Free Energy, spontaneity, negative, positive, enthalpy, temperature, entropy, equilibrium
🤔 Part C: Critical Thinking
Explain how temperature affects the spontaneity of a reaction, considering both exothermic and endothermic reactions, in terms of Gibbs Free Energy. Provide an example for each case.