In this lesson students are introduced to acids and bases through performing an activity.
For this lesson there are several resources needed at each lab station:
In this section of the lesson students are performing their acids and bases intro lab with their partners.
Before students begin the lab I go over what they will be doing in the lab.
I give students 4 minutes per station and then have them rotate.
As students work I walk around to ensure that they stay on task.
As students complete their labs I have them turn into my basket. I then grade their labs using this rubric.
The most difficult part of the lab for students is coming up with generalizations about acids and bases at each station. It is in their nature to just summarize what they saw, but my goal is for them to come up with a generalization for each station. For example at station 1 they should have that both acids and bases conduct electricity and for station 2 they should have that acids make blue litmus paper turn red while bases turn red litmus paper to blue.
Here are two student examples which show how they made observations and then generalizations for each station:
Student example # 1: In this first example, which is characteristic of many of the labs that got turned in, the student did not make complete generalizations about acids and bases in stations 1, 2, and 6. For station #1 the student just said that they all conduct light but did not specify acids and bases. For station #2 the student gave specifics about the four substances and did not generalize about acids and bases. For station #6 the student just said that the temperature increases but again was not explaining her though fully in terms of acids and bases.
Student example #2: In this second example, the student did a great job of coming up with generalizations about acids and bases for each station and could be used as a key when you do the lab with your class.
In this section of the lesson I build on the introduction to Acids and Bases from the lab by having students take notes. They take notes on their notes graphic organizer while I present information on the PowerPoint.
To evaluate students' learning in this lesson I have them complete a homework assignment. I pass out the homework and let them know that they are responsible for completing the assignment at home. I then stamp the homework for completion at the following class and review using the answer key.
Some of the common mistakes by students includes figuring out the conjugate acid/base pairs and writing the conjugate acid or base. I make sure that as I am reviewing the homework that I go over how to figure out the partners (with the only difference being an H+) and also go over how you can differentiate the acid from the base (acid is the proton donor so has the extra H+).