Exploring pH
Sections
1. Introduction
2. Hardware Check
3. Calibration
4. Gathering Data
5. Examining Results
1. Introduction
We're going to measure the pH of some common solutions. But first, hypothesize whether each solution will be an acid, base, or neutral. Then select it in the table below.

The solutions listed are suggestions. If you're using a different solution, enter it in the table.

Solution Acid (pH < 7) Base (pH > 7) Neutral (pH 7)
       
       
       
       

2. Hardware Check
Next we're going to calibrate your pH probe. Make sure your pH probe is connected to one of the pins labeled IIC on your Arduino, and that your Arduino is connected to your computer.
Now we're going to calibrate your pH sensor. You'll need a two buffer solutions. One with a pH of 7 and one with a pH of 4. Here's the procedure for taking a reading with the pH probe:

Procedure:

  1. Rinse the probe with distilled or deionized water.
  2. Dry the probe, especially the tip, with a clean paper towel.
  3. Place the probe in the solution to be measured. Only the tip of the probe needs to be submerged.
  4. When the value stabilizes, click Record to save the value.
So, begin with the buffer solution with a pH of 7, and record a value for it. Then record a value for the buffer solution with a pH of 4.

pH Sensor
0
Buffer pH Sensor Reading
     
     

4. Gathering Data
Using the same procedure we used to calibrate the probe, record a measurement for each solution. When you have a value between 0 and 14 for each solution, you can put away your probe.

Important Always make sure to rinse and dry the probe before storing it in the storage solution.

pH Sensor
0
Calibrated pH Value
0.00
Solution pH
     
     
     
     
5. Examining Results
Below, there's a list of each of the substances we tested along with your initial hypothesis. For each substance explain whether it confirmed or disproved your hypothesis.
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Was your hypothesis confirmed? Explain.
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Was your hypothesis confirmed? Explain.
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Was your hypothesis confirmed? Explain.
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Was your hypothesis confirmed? Explain.
 
6. Lesson Done