Items Due During Week 4:
Section L1: Due in Recitation on Monday, April 20 at 1:10 PM in AC 2501:
Section L2: Due in Recitation on Wednesday, April 22 at 1:10 PM in AC 2501:
A reminder to all sections: start working on the Rough Draft of your Class Presentation paper (which is due during Week 6) once you have selected a Class Presentation topic.
This week we will be delving into the theories used to describe acids and bases. The Brønsted-Lowry theory tells us that acids donate hydrogen ions and bases accept them, but conjugate acids and bases are made in the process. Most acids and bases involve weak systems, so equilibrium constants will be utilized as we calculate pH, pOH and similar related quantities. We will also look at buffers and also titrations. Buffers are chemical solutions that resist changes in pH when attacked or invaded by other acids and bases. Titrations (specifically acid-base titrations) are a powerful analysis tool in the arsenal of the chemist. If you have any questions on this material, please let me know.
Here's what is happening in week 4 of CH 223:
- Explore the material in Chapter 14. There are several tools to help you learn the material.... they include:
- Due: Problem
Set #3 which covers problems from Chapter 14.
- Use this link to get the Spring 2026 version of problem set #3, and use this link to find the recitation video which you can use to self correct your work before turning in to the instructor.
- Included in Problem Set #3 is a Table of Ionization Constants for Acids and Their Conjugate Bases which will be used extensively in Problem Set #3.
- Problem Set #3 discusses buffers and titrations. I will be using the Henderson-Hasselbalch equation extensively to make sense of the concepts (and avoid using double ICE approaches!) - I encourage you to view the "Buffers and Henderson-Hasselbalch Guide" (available here) to understand the power and significance of using the "H-H equation" in this week's material.
- Practice Problem Set #3 might be of help while completing problem set #3; answers are included at the end of the document.
- This Week: Seminar Self Quiz #3 and the (actual) Quiz #3
- All quizzes (Seminar Self Quizzes and actual Quizzes, as well as midterm exams and finals) are closed book / no notes allowed. You cannot use a cell phone or computer; you can have a dedicated calculator and a periodic table (which I will provide) only.
- First, take Seminar Self Quiz #3. You will have 20-30 minutes to complete the quiz, and afterwards we will self correct the Quiz as a class before turning it in. If you are late, or do not attend recitation for any reason, your score will be a zero on the Seminar Self Quiz.
- After taking the Seminar Self Quiz, you will take the actual Quiz #3. Quiz #3 will take about 30 minutes and consist of several 'show your work' questions. Turn in the quiz when done (I will pass back any corrected work I have for you at this time.)
- Sample Quiz 3 (answers at the end) might be useful to help you prepare and study.
- Due: The "Le Chatelier's Principle" Lab
- Bring the completed lab with you to recitation.
- Start: The Acid and Base Titrations Lab.
- I also recommend you start working on the Rough Draft Class Presentation paper
- The "rough draft" for this assignment means at least two typed pages (actual writing, not bulleted 'talking points' or rough ideas, etc.) with at least one science peer reviewed abstract and citation; see the FAQ for more information. Also make sure you include the completed Rough Draft cover page when you turn it in.
- More information about the Class Presentation can be found here.
Here's a preview of what's going to be happening during Week #5:
- Midterm Exam I
- This midterm exam covers problem sets #1, #2 and #3 (essentially Chapters 12, 13 and 14.
- The midterm will have 12 multiple choice questions and four short answer questions. You will not need a scantron to complete the exam, but you will need to mark your answers clearly on the exam itself. You will have 90 minutes to complete the midterm exam.
- The midterm exam will be closed book; no notes are allowed. You will be able to use your calculator and a periodic table (which I will provide.)
- The first and last pages of the exam deserve some comment. The first page of the midterm will include an integrity statement that you will be required to sign. Signing the integrity statement implies that you have not received (and will not be giving) any information on the midterm exam to others that might imply cheating; a failure to sign the integrity statement grants an automatic score of zero, so make sure the first thing you do is to sign the statement. The last page of the midterm exam will be a scoring page which will be filled out by the instructor when the exam has been graded; you do not need to complete anything on this page. An example of the integrity statement and grading sheet can be found can be found here.
- Midterm Exam I details by section of CH 222:
- Section L1 will take the midterm on Monday, April 27 at 1:10 PM in AC 2501.
- Section L2 will take the midterm on Wednesday, April 29 at 1:10 PM in AC 2501.
- To Study and Prepare for Midterm Exam I:
- Watch the Complete Lecture of an Exam Review for the first Midterm Exam here: Midterm Exam Review
- Lecture videos for the Exam Review for the first Midterm Exam will be available on YouTube and as a Podcast.
- A sample exam (with answers) is available on the Chemistry 223 website under Quizzes
and Exams. You can also view the Chapter Guide written for Exam I.
Also happening during Week 5 in CH 223:
- Due: The Exam Prep I worksheet.
- An Exam Prep is a handout designed to help you get ready for the midterm exam. I will not be able to help you with the midterm exam, but I can help you with the Exam Prep!
- The Exam Prep I worksheet will be due at the time of your midterm exam I.
- Due: The Acid and Base Titrations Lab.
- Bring the completed lab with you to recitation
- Start: The Titration of Weak Acids Lab.
