Households Acids and Bases

We were given the following household solutions and had to find their pH.
Vinegar
Ammonia
Lemon juice
Soft Drink (Coke)
Drain Cleaner
Detergent
Baking Soda
Milk

I made a hypothesis for each of what their pH would be.
Vinegar -Acid 3
Ammonia -Base 12
lemon juice -Acid 3
Soft drink -Acid 6
Drain Cleaner -Base 13
Detergent -Base 10
Baking soda -Base 8
Milk -Base 11

We used these materials to help find the pH
-computer
-vernier computer interface
-logger pro
-vernier pH sensor
-wash bottle
-distilled water
-stirring rod
-250 mL beaker
-sensor soaking solution
-household solutions
-8 small test tubes
-test tube rack
-blue litmus paper
-paper towel
-red cabbage juice
-graduated cylinder

We followed these procedures:
Obtain materials and put on the goggles. Remember not to drink or eat in the lab area. Label the test tubes from 1-8. In test tube one, put 3 mL of vinegar. As in the order above, pour 3 mL of the specified solution into the remaining test tubes. [As a note, the baking soda solution must be made with 20 mL of water and 1/2 a tablespoon of baking soda. Stir thoroughly.] Using the dropper, collect some of the solution in the dropper. Remove a slip of litmus paper and drop a few drops from the dropper onto the litmus paper. Compare the color to a pH scale and record the best estimate for the acidity or basicness of the solution. Clean the dropper before the next use. Repeat the test for the rest of the solutions. Don’t empty the solution, instead retrieve some cabbage juice. Pour 3 mL of the cabbage juice in each test tube, and in between record the acidity or basicness of the solution. Dump each of the test tubes contents when you are done. Refill the same liquid in the same container. Unpack the probe and connect to the computer via lab quest mini. Open the file called “21 Household Acids” from the Chemistry with Vernier folder. Remove the sensor from the storage solution, and don’t spill it. Rinse the tip of the sensor with distilled water and put it in the first test tube. When the number on the computer stabilizes record it on a chart. A good example of the chart can be found in the results section. Remove the sensor, and rinse with distilled water. Put it back in the storage solution, and then remove and rinse again with distilled water. Put in the next test tube and continue the pattern. When you are done, rinse the sensor in distilled water and put back in storage solution. Pack up your materials and dispose of solutions.


Some of the results we ended up with were different than our hypothesis, and some were the same. The following chart is our results.

Test tube	solutions	blue litmus paper	red cabbage juice	pH
1	Vinegar	Acid 2	Acid 2	2.64
2	Ammonia	Base 12	Acid 6.5	11.31
3	Lemon juice	Acid 2	Acid 2	3.27
4	Soft drink	Acid 3	Acid 3	2.97
5	Drain cleaner	Base8	Acid 5.5	12.69
6	Detergent	Base 10	Base 10	9.98
7	Baking Soda	Base 9	Base 8	7.91
8	Milk	Base 9	Base 9	6.57

This is a picture of the sensor in our 5th test tube.







This is a picture of us cleaning the sensor.


This is when we labeled the test tubes.

This is a shot of one of the pieces of litmus paper.


This table compares my hypothesis’ and my results.

Solution	Hypothesis	Result
Vinegar	Acid 3	2.64
Ammonia	Base 12	11.31
Lemon juice	Acid 3	3.27
Soft Drink	Acid 6	2.97
Drain Cleaner	Base 13	12.69
Detergent	Base 10	9.98
Baking Soda	Base 8	7.91
Milk	Base 11	6.57

Conclusion: I got the majority of my hypothesis’ confirmed. Some of them were complete opposites of the hypothesis, but most were extremely close to my guesses. I think that if we were to do this again we should have more items to test, even some tests that are harder.
We even had the chance to see that the pH of the storage solution for the pH sensor. It was acidic and turned our litmus paper red. When the probe was in it, it said that it had a pH of about 3.5. We should have more opportunities for testing the different materials.