Inquiry Chemistry

I thought that the lab worked as a guided discovery into how one would "drive off" the water in copper sulfate pentahydrate. Prior to the lab I heard three different questions. First, was there water in the "copper sulfate." Second, how could you prove that there was water in the "copper sulfate." And third, how much water was in the "copper sulfate." When we got to the lab we could choose from a heat source, copper sulfate pentahydrate, test tubes, ceramic cups, gloves and test tube clamps, and a scale. We had already been led through three calculations to find percent change in word problems that included a reduction in grams. We were told that we would need to use a similar calculation in the lab. The set up was excellent and there really wasn't a great deal of variety in approaches to "proving" that there was water and determining how much water we drove off through heating the substance. Again, I thought that the experiment was masterfully prepped, all participants were comfortable with the experiment and everyone was able to successfully drive off some water. It was certainly a good opportunity to talk about variation in answers and what variables are, as well as an opportunity to talk about why procedure can be vital.

My reaction to the experience posed a number of questions for me. Chief among them is whether or not I label an activity as inquiry if the question and outcome are so tightly controlled and forgone conclusions and if the procedure is so tightly controlled as to not allow (for safety or expediency) any variation in approach. (I'm thinking about the girls in the video who tried adding water and were told that they needed to walk around the room and see what others were doing--we talked about this in the morning session--and I do hear Paul's concerns about efficiency, not letting kids go too far off course and "learn it wrong," and safety concerns in a chem lab if too much is left to student choice.) Given these givens/constraints, I don't think we have to label everything that comes with a question as inquiry. I am also wondering if there are ways around the three concerns in a typical high school classroom--for instance, submit your proposed lab procedure to me before beginning so I can head off any potential explosions or toxic plumes?

The lab took me back a few years, and I felt led---it was copper sulfate pentahydrate, we were to weight it, drive off water using heat and calculate (using %) the change in weight. My learning style always did much better with labs like this when the teacher just told me up front that this was the plan.

So, on the train ride home, I started to wonder how I might adapt this experiment for use with my students. I was thinking that I might do something like this with 5/6 graders:

Remember last week when we talked about how small a water molecule is? It was pretty cool right? Does anyone remember the chemical shorthand for water? H2O. Right. so, I have a new chemical name for you---CuSO₄·5 H₂O  

Get out your whiteboards and colored markers. If I had a container full of this stuff, what do you think something with a name like this might look like?

Now, use descriptive words to tell me how you would experience it with your senses. What do you think it smells like? tastes like? looks like (color, texture...)? sounds like? feels like?......Just make a list on your whiteboard. Prop them up and walk around the room. As you take a look at your classmate's ideas, notice if we have a lot of similar ideas or different ideas.

(I am guessing that at the 5/6 level, we'll get some descriptors that say it is a wet something--after all there are 5 water molecules for every "something new molecule.")

After talking about what we notice about our ideas I'll ask, Okay--are you ready to see what this stuff looks like?

Then I show it to them--either on the screen or in a petri dish.

We'll talk about their assumptions when they drew their pics (we draw representations to imagine what things look like all the time--so this isn't a threatening enterprise for them--they think of it more as a game and are more that okay when they are surprised by the unveiling), we'll get to talking about how some things that include water molecules are not wet, we'll share other examples, we'll swing back around to how small that water molecule is. Which for us is really the point--because at grade 5/6---I've got to shift their thinking from water in a glass to water molecule--it is an expansion of the use of the word WATER.

Then I will ask them if they want to do a fairly common experiment that science teachers use to "prove" that there are water molecules in the crystals. We'll drive off the water the same way we did in Paul's lab today and we'll talk about what they saw.

All of this has been guided discovery. Next step, an attempt at setting up an inquiry.

If I am really lucky--and thank the stars, 99% of the time I am if I give kids enough down time to talk to each other about what just happened-----one of my students is going to ask if they can prove that there is water in something else---and this will launch the great water molecule hunt/inquiry. The kids will leave trying to think of something that they can bring in to test for the presence of water molecules. They'll need to develop a totally different methodology---I don't want them to repeat the class experiment--I want them to surprise each other and me with their creativity. And afterall, if they want to prove that their best friend is made up in part by water molecules, they can't just go heating them over the hot plate in the room. They can work alone or in pairs. As an extra challenge they can bring a second thing in to school that goes into the stump box--something that they do not believe contains any water molecules. Anyone in the classroom can refute an objects inclusion in the stump box as long as they can back up their argument.

The last step gets closer to inquiry for me, because it is motivated by student question, design, and analysis of observations. It also has the potential to have some surprising outcomes. I have no idea how many different ways my students will come up with to test for the presence of water molecules. Throughout the whole experience, they will be exercising agency, talking and sharing with each other, confirming their sense that water molecules are "this small" and that their presence does not always mean wet. They'll also be working through how to ask questions, set up a science inquiry, interpret observations, apply skills, use communication to see how others approach a similar question and think about how they can listen to others to fine tune their own thinking. I could have students use the inquiry reflection questions in the model Brie posted to think about their work in this last step.

I keep coming back to our discussion of how inquiry requires space. I don't think that everything we do has to be or be labeled inquiry. Especially when you think about all of the different learning styles in a room--we need to mix it up---direct instruction, some guided discovery, inquiry....we've got a lot of tools/approaches to offer kids. I do think that inquiry is awfully important--we've got to find time for it, kids need to learn to ask questions and construct meaning for themselves----because life doesn't come with a text book and it sure isn't anything like any paper and pencil test I've ever taken!