The Great Debate: Sugar vs. Salt

In my most recent foray into GRITTY problem solving in my science classroom, I posed the following question to my grade 11 AP Chem class: “What dissolves better in water: sugar or salt?” This relates directly to our solutions unit, and fit with the day’s lesson, Solubility and Saturation.

Side Bar: one of my greatest challenges with my Action Plan has been making and implementing authentic learning tasks that align with curriculum closely enough so as not to seem random. The students should be able to connect & relate to the task at hand.

After allowing them some time to ponder the question, I asked them to make a hypothesis and asked a few students to give reasons for their predictions. (I have done this four times. Each time, invariably, the majority of my class thinks salt will dissolve better.) As all scientists know, after making a hypothesis, it needs to be tested. So I posed my class more questions: “How can we test this? What do we need to consider?”

And so, my students started to think of control variables: using the same volume of water in both trials, keeping the water the same temperature, adding the same amount of salt and sugar to each beaker, using the same stirring technique. Then, I chose some volunteers to conduct the test (and one student to be the “judge” and ensure that it was conducted fairly). Within 2-3 scoops, the superior solute was identified.

I won’t spoil the outcome of “The Great Debate” (leave a comment if you have a hypothesis and a reason WHY), but overall it was quite successful at demonstrating the differing solubility of various solids in water. It also naturally flowed into the topic of Saturation, and prompted questions from my students like “How much sugar is in a can of pop? What does that amount of sugar actually look like?” (They weighed it out on a scale).

Once again, my classes proved their ability to problem solve, by carefully planning and executing a successful experiment to test their hypotheses. For at least the second time, my group of “guinea pigs” demonstrated more GRIT than I anticipated. This caused me to reflect a little bit on my Action Plan and “How Might We” question. I was drawn towards this “problem” by a lack of GRIT in my summer school Physics class. In order to address that issue, it might be more prudent for me to develop GRIT in my grade 10 class (those who will take Physics over the summer) rather than look for GRIT in my more advanced grade 11 class (those who are currently taking advanced Physics). I will definitely continue these authentic problem solving tasks in all of my classes, but work extra hard to develop skills and strategies with my younger classes.

Special Thanks to @ddoucet and @egelleny for kicking my butt encouraging me to write this post.