Gibbs Free Energy

Chapter 18: 6-7 Homework

Reading Preparation
WebLecture
Study Activity
Preparation work for chat
Online Quiz
Lab Instructions

Reading Preparation

Textbook assignment: Read Kotz and Triechel, Chemistry and Chemical Reactivity Chapter 13: Sections 6 to 7.

Study Notes

18.6 One way to summarize the relationship of entropy and enthalpy is the Gibbs free energy equation. Any change either requires energy (endergonic) or releases energy (exergonic); this energy change is the enthalpy of the change, and in chemistry, the enthalpy of the reaction, ΔH. Some energy will be lost or gained from a change in entropy ΔS where the energy amount depends on the temperature at which the change occurs. The difference between the enthalpy of the event and the change in entropy is the "free energy" ΔG: ΔG = ΔH - TΔS. If ΔG of a system is negative, the event is exergonic and the change is favored and spontaneous.
18.7 ΔG is a state change. Δ_rG is the change in free energy for a chemical reaction; Δ_rG° is the change at standard temperature and pressure. We can predict Δ_rG at any condition if we know Δ_rG°, the temperature, and the reaction quotient Q from the relationship.

Key Formula

Principle	Formula	Notes
Gibbs Free Energy	$G = H - TS$	G: Gibbs Free Energy H: Enthalpy Δ: Change R, k: Constants T: Temperature
Gibbs Free Energy Change at STP	$Δ G^{o} = Δ H^{o} - T Δ S^{o}$
Gibbs Free Energy, any Temperature	$Δ_{r} G = Δ G^{o} + RT \ln Q$
Change in Gibbs Free Energy at STP	$\begin{matrix} Δ_{r} G^{o} = - RT \ln k \end{matrix}$
Free Energy of Formation	$Δ_{r} G^{o} = {Σ n Δ}_{f} G^{o} (P) - {Σ n Δ}_{f} G^{o} (P)$

Read the following weblecture before chat: Gibbs Free Energy

Study Activity

Videos for Chapter 18: Principles of Chemical Reactivity: Entropy and Free Energy

Review the Videos at Thinkwell Video Lessons.

Under "THERMODYNAMICS"
- Gibbs Free Energy and Free Energy Change
  - Gibbs Free Energy
  - Standard Free Energy Changes of Formation

Use the instructions at Investigating Entropy in Chemical Reactions from SciencebySimulation and the linked ChemReaX simulator to conduct the endothermic virtual reaction. How does changing temperature affect free energy changes? How does changing temperature affect entropy changes?

Chat Preparation Activities

Essay question: The Moodle forum for the session will assign a specific study question for you to prepare for chat. You need to read this question and post your answer before chat starts for this session.
Mastery Exercise: The Moodle Mastery exercise for the chapter will contain sections related to our chat topic. Try to complete these before the chat starts, so that you can ask questions.

Chapter Quiz

Required: Complete the Mastery exercise with a passing score of 85% or better.
Go to the Moodle and take the quiz for this chapter.

(Aligns to) AP #15 GUIDED INQUIRY — Titration Methods — Phase III

Complete your analysis; redo your experimental runs if necessary, then post your formal report.

Resources:

AP2009 #6 Standardization of of solution using primary standards
APGIE Investigation 14 Acid-Base Titration: How Do the Structure and the Initial Concentration of an Acid and a Base Influence the pH of the Result Solution During a Titration?
IGHCE Lab 11.4 Standardize a Hydrochloric Acid Solution by Titration
There is no alternate form for this lab

© 2005 - 2025 This course is offered through Scholars Online, a non-profit organization supporting classical Christian education through online courses. Permission to copy course content (lessons and labs) for personal study is granted to students currently or formerly enrolled in the course through Scholars Online. Reproduction for any other purpose, without the express written consent of the author, is prohibited.

Chemistry

Chemistry 18: 6-7