STEM Chemistry at GBS
Home Page

Home || Schedules || Laboratory || File Cabinet || Quiz Room || Helpful Resources

Unit 5 - The Thermodynamic Model of Chemical Reactions

There will always be more to the "story" of Chemisty and in this unit, thermodynamics is the "more" that we will add to our growing understanding of chemical change. We will learn that the change in temperature that occurs when a reaction takes place is associated with the energy required to break bonds and reform new bonds. We will learn how to measure this energy using a method known as calorimetry. And we will learn how to use energy and entropy to predict whether or not a given change will take place. Our ideas will apply to the very small - to atoms and particles - and apply to the very large - to the universe as a whole.

We will be testing on about the 9th block of the unit. There will be several labs, the usual battery of WebAssigns, and a chemistry-engineering project that will run alongside the execution of this unit. Ideas are both conceptual and mathematical. Bring your calculator every day as you will be using it quite regularly.

Thermodynamics - Notes

Some important terms were discussed on Days 1 and 3. Some abbreviated notes are provided online:

View Day 1 Vocabulary Terms

View Notes on Endothermic vs. Exothermic Processes

Quiz Key

Friday's Quiz has been graded and the quiz key is posted online:

View Quiz Key.

Hear Ye! Hear Ye! The End is Near!

The End is NearThe Unit 5 Test is on Tuesday, February 19. The test will include ~18 multiple choice questions, 6 long-answer problems, and a hands-on lab problem.

There are several good ways to review for your Unit Test. These include going over your Unit 5 Packet, reviewing the textbook readings, going over Past Due WebAssigns, and doing the optional Unit 5 Review WebAssign. As in the past, there will be an optional, no-point WebAssign Review available that covers topics from the entire unit.

Unit 5 Labs

We will be doing the following Unit 5 Labs. Lab description pages can be found in the Laboratory section of this website. The links below lead to those descriptions. Notebooks will be collected on Tuesday, February 19.

What is Meant by "Annotating" in a Lab Report

We tend to do two types of labs - (1) labs that include multiple observations in an effort to identify properties and trends in those properties and (2) labs that include careful measurements and subsequent calculations in an effort to determine an unknown quantitative value. When doing the second of these two types of labs, there are several measurements followed by an extensive set of calculations. The Conclusion section is generally short but the Calculation section is long. The role of the Calculations is to document and present the logic as to how the measurements lead to the quantitative value that the lab proposes to find. A good presentation of measured data and calculations will include annotations. Annotations are short notes that convey what the subsequent calculation involves and the logic behind it. The concept of an annotation was discussed in class on Tuesday, December 6. For those who would like to review the discussion, the notes are provided here.

View Notes on Annotations.

Help is Here

The following resources will be quite helpful supplements to your textbook readings. The resources included Tutorials, YouTube videos and practice.

Periodic Table in Pictures and Words

For those who are connoisseurs of periodic tables or simply would like to relish a great moment of geekery, tap the link below and explore on this interactive periodic table of the elements.

Visit Interactive Periodic Table with Words and Pictures.

Mr. H's Little Secret

Pssss.  Hey bud! I have a secret to share. Now that you know how to calculate the molar mass, here's a little cheat you should be permitted to use. It's called a Molar Mass Calculator and you will find several by following the links below. You type in the formula and it calculates the molar mass.

WebQC Chemical Portal (one of my favorites)

EndMemo (allows formula or name entry)

Environmental Chemistry (scroll to bottom)

Molecular Weight Calculator by Lenntech

or Google, e.g. molar mass Al2(SO4)3

    Online Homework


This page changes nearly every day; re-load or refresh to receive the most recent schedule.

Today in Class

>> Thursday, February 14 <<

Focus Question(s):
  • How are entropy change and enthalpy change related to spontaneity of reactions?
  • How does one use Gibbs Free Energy to predict whether a reaction is spontaneous or not at a given temperature?

  • Review Entropy; p. 20 side margin notes; do p. 23, Q#1-5
  • Discuss driving forces (p. 24, Q#7)
  • Discuss Spontaneity; p. 25, Q#1-2
  • Discuss Gibb's Free Energy equation
  • Spontaneity and Free Energy (pp. 27-28)
  • Work Time:
    • Complete Lab TC8 - Hess's Law
    • Work on WebAssign

  • WebAssign: Gibbs Free Energy
  • Complete Lab Notebook


Next Time in Class

>> Tuesday, February 19 <<

You will receive your Unit 6 Packet. We will discuss states of matter with an emphasis on gases and gas pressure. We will take the Unit 5 Test. Part of this test will include a Lab Practical. You have 15 minutes to gather data and clean up your station. You are provided general directions and no data table.

Periodic Tables

Are you in need of a periodic table?  Try one of the following websites:

Home || Schedules || Laboratory || File Cabinet || Quiz Room || Helpful Resources