In this lesson students learn about how solutions are formed and how to describe solutions qualitatively. This lesson builds on what they learned in the previous lesson, Introduction to Solutions.
For this lesson the only special resource needed by students is access to computers for the PhET activity.
To begin the lesson I remind students that we are beginning a new unit about water quality and that we are starting by talking about solutions.
I also tell them that, "As we discuss solutions today you should think back to the four solutions that we made last class period."
In order to help remind students I have a set of the four solutions at the front of the classroom.
During this section of the lesson I teach students about solution formation, how to express solutions qualitatively, and how to read solubility curves. I present information on the PowerPoint while students take notes on their notes graphic organizer.
To help reinforce the idea of solutions and how to express solutions I have students perform a PhET computer simulation. The simulation is called concentration and is available online on the PhET website. The goal of the simulation is for students to understand how solute and solvent relate to the formation of solutions and solution concentration.
I pass out the phet lab paper to students and have them go up to a computer with their table groups.
As students are working I walk around to help make sure that they are all participating and to answer any questions that they may have.
Overall, this activity is fairly straightforward to students so they do a good job of being able to understand how various factors affect solution concentration.
This is an example of one student's completed lab. Notice how this student does not fully answer the questions for #4 and #5 in terms of WHY but then does so for the last few questions.
To complete this lesson I have students do a homework. I have them start the homework at the end of class and then complete at home.
I stamp the homework for completion at the following class and then go over the answers using the answer key.
Here is a copy of one student's answers to the homework.
Some of the common mistakes by students include: