Students are told that they have to determine the amount of active ingredient in an antacid tablet. Then I ask them if they have any questions. First it starts with blank stares...then slowly the questions start coming. What exactly is the active ingredient? What does it react with? They are provided information that the active ingredient is baking soda.
The ACS Committee on Chemical Safety has published new Guidelines for Chemical Laboratory Safety in Secondary Schools. This document is organized with the R.A.M.P. concept – Recognize the hazard, Assess the risk of the hazard, Minimize the risk of the hazard, and Prepare for emergencies. The online document includes two pages for each letter that could be printed and posted in the classroom to reinforce these principles of safety. The documents are provided to strengthen the safety practices of teachers and help them to promote a culture of safety that their students will take with them throughout their academic and professional careers.
For years my students would heat the hydrates in glassware, burn themselves, break the glassware and splatter salts and thus their data, all over the lab bench. A few years ago Bob Worley came up with a great microscale technique. Essentially, it takes a used bottle cap without the plastic and this is used as the dish. Next, there is about a three inch machine screw that goes through a drilled hole in the cap. A nut is placed on the screw to hold everything in place and cheap pliers are used to hold the entire assembly over the flame.
How do teachers encourage building individual lab skills in classes of over 30 students where labs are done in groups of five or six students? My science department collaborates daily, and we have been discussing this concern for a few years now. Many trials and errors have occurred.
Just this week I'm reviewing equilibrium with my IB Chemistry seniors after they finished some summer study on the topic. One of our classes was spent manipulating a classic equilibrium involving copper ions and a copper-chloride complex ion.
I am a very firm believer that the world of physical science can be visualized and is an excellent medium for teaching students to model and to picture what happens at the molecular level. The first topic we decided to explore was balancing chemical equations. This seems like such a simple topic to chemistry teachers but I have found that it can be quite challenging for many of my inner city students. The first thing they ask me for is a list of rules that they can follow. We can discuss the problems of algorithmic teaching in a later post! For the time being let’s talk about how to get students to understand why they need to balance equations and discuss what we can call “Conservation of Atoms”.
One of my biggest struggles with students is to try to explain what happens when items, specific inorganic salts, dissolve in water. It might sound simple to me and you. Research shows that students have many real misconceptions when it comes to explaining inorganic salts dissolving in water. My own experience along with other teachers I know is that we are amazed and sometimes frustrated with trying to help students understand the simple process of dissolving, especially with ions. A key piece of equipment is a good conductivity tester. Just got done making a stack of them and can't wait to have students try them. But back to "dissolving"....
Back to school time means back to lab time too. Students new to chemistry have a lot on their plates the first few labs—learning unfamiliar safety procedures, becoming accustomed to writing lab reports, even figuring out which glassware they’re looking for in their lab space. How can teachers help them to navigate this newness? Two articles in the July 2016 issue of the Journal of Chemical Education are useful resources for “back to lab” time.
This past week, as part of our Thermochemistry unit, my students were completing one of my favorite Target Inquiry Labs entitled “ A Very Cool Investigation”. We were using calorimeters, dissolving ammonium nitrate, and my students were recording the change in temp
For my students and me, the AP Chemistry exam does not mark the end of the school year. Once the AP exam is over, my students are exhausted but our class continues to meet for three more weeks. Each year we complete a qualitative analysis lab, but this year we finished earlier than I anticipated. For the first time all year, I have the luxury of time.