Saturday, November 9, 2013

Chemistry JiT #4: The Mole & Stoichiometry

I tried posting this the day of the training and had uploading issues. Anyway, the 4th Chemistry Just-in-Time (JiT) training was held for teachers about two weeks ago. I met with my Region  Service Center counterpart, also a former teacher from my district, in order to plan for the Chem JiT workshop.  As mentioned in an earlier blog post, the workshops are geared toward upcoming standards in our scope and sequence in order to provide teachers with ideas and/or activities to utilize in the classroom. Additionally, we adjust our sessions based on teacher feedback. A majority of the feedback we have received has been positive; all cool feedback resulted from insufficient planning time with campus based PLCs [although, I would argue they had plenty of time ;) ]

Let me get straight to sharing one of the activities via pictures and descriptions...

One of the first activities that was shared was part of an introduction to the mole concept I developed 2-3 years ago when I was still in the classroom. I had always introduced the mole concept by showing students a dozen of several different items - a dozen doughnuts, a dozen pencils, etc. However, reflecting back on my experience as a chemistry student, I remember still struggling with what a mole was/meant even when my teacher explained it that way. All the conversion factors (1 mol = molar mass (g), 1 mol = 6.02x10^23, 1 mol = 22.4L) were too much to handle when learning this topic for the first time; in addition, MATH was involved. 
So, the first thing I had my students do when class started was to go to their assigned lab table and find  at least four different substances.  The first time I did this I used large paper clips, beads, cheerios, and toothpicks as I had thought of the idea a day before implementing it and needed a large quantity of items fast (the types of items do not matter as we had to substitute  materials at the training because our requested items were not prepared). 

At the station, I ask students to create 3 groups of a dozen and weigh each group separately. After, students answer a few questions that scaffold the overall purpose of the activity.This task may seem extremely elementary, however, it has helped me tremendously while teaching the mole concept. 

First, I am driving home the point that we have words that represent a certain quantity (1 dozen = 12 items; 1 mole = 6.02x10^23 particles) no matter what we are talking about. Most students will recognize this fact. Secondly,  students can develop a general relationship between quantity and mass. Looking at the pictures above, the mass of each group of cubes is approximately 12.0 grams. From here, students could develop a general rule that 1 dozen blue cubes = 12.0 grams and use that information to calculate problems or unknown situations in the future. Students also realize that the number of blue cubes and yellow circles is the same - a dozen each; however, the substances do not weigh the same. 
After completing the activity, teachers were asked to develop a concept map or other visual that would help them process the activity (as if they were students themselves). Even if you do not use interactive notebooks, I would suggest allowing students time to process the information that makes sense to them (drawing, concept map, acrostic, etc.). I really like how a few teachers drew 12 blocks and 12 paper clips to indicate the same quantity and showed how they may not necessarily have the same mass.

When I originally did this activity, I wrapped up and went straight into the mole concept. I constantly referred back to the activity to help students process the information. I will say this activity made teaching moles much easier the last 2 years I was in the classroom.

UPDATE: This post is was written in 2013; however I have used the idea since 2010. I recently developed an interactive notebook product specifically for the mole concept and have included the activity in a note-format, which may be found by clicking here or on the picture below. 

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