Activity Overview
In this activity, students' will use a pH sensor to record pH versus time data as an antacid tablet neutralizes acid in lemon juice. They will model the pH data with a modified exponential function.
Before the Activity
Connect the pH probe to Channel 1 on the CBL 2™ or Vernier LabPro®
Connect the CBL 2 or LabPro to the calculator using the Unit-to-Unit cable
See the attached PDF file for detailed instructions for this activity
Print pages 199 - 205 from the attached PDF file for your class
During the Activity
Distribute the pages to your class.
Follow the Activity procedures:
Place about 125 ml of distilled water in a very clean cup
Place the pH sensor in the water
Add drops of lemon juice to the water and stir gently
Drop the effervescent tablet into the water and measure pH every 0/5 seconds for 50 seconds
Plot the pH versus time graph
Use a modified exponential equation to model the data
After the Activity
Students will analyze data and complete the Data Collection and Analysis Sheet. They will also answer questions listed in it.
Review student results
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary