I first did this inquiry activity for teaching factors that affect solubility when I was student teaching. Well, actually it was during my teacher observations during my degree program. I was matched up with a really great teacher, who not only had me observe her teaching, but also let me get involved in her class. It was actually a really rewarding experience.
Should you teach it first, or let kids discover it?
During my time there, I was asked what I thought would be best: teaching a lesson on the factors that affect solubility, or giving the kids a lab to have them learn it themselves. The teacher explained that she did different things depending on how much time she had in her pacing calendar.
Honestly, both work. Your kids probably already know what the answers are. I mean, they are humans that exist in the real world. This lab isn’t really that mind blowing. The real important part here is the inquiry process. And because they know the answers, it actually helps to show them that they can only test one variable at a time. It teaches them the concept of a control group. And they see it in action. I think it’s a great way to teach about the scientific process, more so than the factors that affect solubility. Interested in my lab rubric? Sign up here, and I’ll email it to you.
She had a bunch of materials, but had me draw up something on my own. We talked about how I would work out this lab activity and how I would explain the task to the kids. Based on the materials available in the lab, I came up with a procedure, and drafted the worksheet. It has since evolved to fit my specific needs but here’s roughly how it goes.
Factors that Affect Solubility Lab Activity
I start by asking my students how they think solids best dissolve in liquid. They come up with a hypothesis during our pre-lab lecture. I also ask them about their hypothesis for gases during this time, but I teach that a few days later.
The gist of the lab is getting the kids to uncover what makes factors affect the solubility of solids. I give my students some sugar and a sugar cube. They are tasked with dissolving equal amounts of solute under different conditions. They test hot versus cold water. Surface area of the granulated sugar is compared to the sugar cube (they’re 2.5 grams, FYI). I’ve also had them test concentration by changing the amount of water, or sugar. Both can be done. And finally, the students also test agitation of the solution.
Testing the Hypothesis
The students do this on their own and test their hypotheses. To be honest, many of the students are going to make the correct hypothesis. Once they sit and think about it, they already know the answers. But I don’t see any issue with them putting two and two together. While this lab is an inquiry activity for teaching the factors that affect solubility, the students truly learn the inquiry process. They have a question, a hypothesis, investigation and reporting.
Solubility Lab in Physical Science
I’ve also really liked using this lab activity for physical science students. Factors that affect solubility isn’t part of the physical science curriculum. This activity is better suited for illustrating independent and dependent variables, as well as the importance of testing a single variable at a time. This lab didn’t start out this way, but I’m really glad that I’ve been able to dual purpose this activity for both of my science classes. It makes things a lot easier for my planning purposes.
Get this lab activity from my Teachers Pay Teachers store. Interested in other activities for teaching about solutions? Check out this post on freezing point depression.
