In this lesson students are continuing to learn about Acids and Bases in terms of how to express these types of solutions quantitatively. They do this through taking notes, making a chart, and performing a practice question with a partner.
For this lesson there are no additional resources needed.
I begin this lesson by introducing students to the concept of pH, the pH scale and calculations involving pH through a PowerPoint. Students are a little familiar with the material because they were introduced to the pH scale in the previous lesson, Introduction to Acids and Bases, with station 7 in the introduction to Acids and Bases Lab.
To help reinforce the pH scales and give students practice with using the equations I have them perform a Practice Paper.
I start by passing the paper out to students and then leading them through doing the front section.
I have them start with Part I and I model how to fill in the chart. I tell them that they do not have to write the standard notation for H+ and OH- but that they should notice the ones already done to get a visual of the quantities. I do the first few rows with them and then have them complete on their own.
As students finish Part I, I lead them with Part II. I encourage them to use markers to label the different parts of the chart. I have them start with neutral, then do the acids, and finally finish with the bases.
With Part III I try to get students to see how the equations that relate these four quantities make sense. Students have a fairly easy time with the first one, but find the other three more difficult. This movie shows me helping students with seeing the relationships between the quantities in equation form.
After reviewing the equations I have students do part IV on their own. I encourage them to use their calculators as well as the chart on the front page to help them. I also tell students that this is a great time to make sure that they understand how to plug these values into their calculators and to ask me for help if they are having problems.
As a way to check that students are understanding how to use their calculators and how to plug and chug with the new equations I finish the lesson by having students do a practice question with their partner.
I give each set of partners a question from the unit 8 group practice paper . On the paper each group has a unique value for H+ and from that have them determine the pH, pOH, OH-, and if the solution is acidic or basic.