In this lesson students are introduced to the concept of equilibrium and Le Chatelier's principle through performing an activity, taking notes, watching videos, doing whiteboard practice, and doing a practice worksheet.
For this lesson each group of students needs 100 two-sided papers with Product on one side and Reactant on the other for the engage activity.
To begin the lesson I have students perform an activity with a partner where they are able to visualize what happens with reactants and products during an equilibrium reaction.
As a second part of the lesson to engage students I have them think about several questions on the first slide of the PowerPoint.
The questions include:
I tell them to think about them on their own first and then to share with their table groups.
The goal of my doing this is to give students a chance to review what we learned in the previous lesson before learning new content.
I give students several minutes to do this and then call on several groups to share out their answers with the rest of the class.
For the most part students remember these concepts from the the first lecture, and if they forget than they know to look back at their notes and/or talk with their partners.
This is a copy of one student's filled in notes with the answer for this section at the top of the paper.
This part of the lesson is where I teach students about equilibrium and Le Chatelier's Principle. I present the notes to students on the unit9 lecture 2 PowerPoint and have them fill in information on their notes graphic organizer.
For this section of the lesson I have students perform practice questions of Le Chatelier's principle which are on the last 3 slides of the PowerPoint.
Students are still very unsure of how to do Le Chatelier's Principle so I make sure to go through each of the questions with them one at a time.
For example I first show them slide 12 and have them try questions #1. I then go over the answer and then have them try question #2, etc.
Here is a copy of one student's notes which include the answer to the practice questions at the bottom of the second page.
To help reinforce Le Chatelier's principle I have students watch the videos for two chemical reactions. I choose to do the videos versus real-life demonstrations because it is much easier and less time consuming with the end of the year crunch.
I start by passing out the Equilibrium Video Questions paper.
I then tell students how we are going to first focus on the first reaction and to look over the questions that we will be answering. I tell them to take a second and predict the answer before the video.
I then show students the first video LeChateliers-Cobalt Equilibrium movie.
I show them the entire video one time. I then start it over again and during the second time I pause for them to answer the questions. The final question "is the reaction exothermic or endothermic" is not on the video, but I tell students they should be able to figure it out by looking at the equation.
Next, I tell students that we are going to focus on the second equation. I tell them to look over the questions and to try to predict the answers before the video. After several minutes I show students the second video NO2-N2O4Equilibrium-Pressure movie. I play the entire video one time. Then during the second time I stop so that they can answer the first question.
I then show students the third video Demo-NO2-N2O4- temperature movie. I show them the entire video one time. I then start it over again and during the second time I pause for them to answer the last two questions.
As a final part of this lesson I have students perform homework.
I pass out the homework worksheet and let them know that the paper will be due at the next class.
At the next class period I check their homework for completion by stamping and then go over the answers using the answer key.
This is a copy of one student's paper with their answers to the questions.
At the end of each class my students have SMI time. For this SMI period students worked on test corrections from the last exam (Unit 8- Water Quality).
When students perform test correction in my class I have them use a paper where they write down each incorrect answer, what the correct answer is and an explanation of why that answer is correct. For their explanation they can write a sentence for the "wordy" fact-based questions, and must show their work for the "mathy" equation-based questions.
When I grade students test corrections I grade it using a check (100%) where students completely explain all of their incorrect answers, check minus (75%) where students are missing a question or two or missing their justification, and check minus minus system (50%) where students are missing several of their incorrect answers.
This is a copy of a student who earned a check. If you notice they explain why the correct answer is correct and show their work for the answers that that are "mathy" like solving for ppm in #9.
This is a copy of a student who earned a check minus. Notice how this student does not completely explain WHY the answer is correct in #13 and has incorrect work for #19.