General Activities Unit
TESTING SOAPS
Purpose:
Test different brands and types of soaps to see which offers the best buy to the consumer.
Materials:
Science CAP 2009 Testing Soaps.doc
General Activities Unit
* water
* grease
* oil
* mirror
* dried leaves
* saucer
* two dishes
* eye dropper
* Crisco solid shortening
* babyfood jars
* salt
* food coloring
* plastic bowl
* pH paper
* different brands of dishwashing soap
Science CAP 2009 Testing Soaps.doc
General Activities Unit
DISH SOAP EXPERIMENTS
On a piece of paper make a chart for your group listing on the top the various brands of soaps used, and along the side, the experiments done on that brand.
* Try one brand of soap and record the results from all of the experiments, then try another brand.
* Try to get all of the results before doing any others, so that we will have enough data.
Level of suds:
1. In a baby food jar, put in water to a level of 3 cm.
2. With an eye dropper, put in one drop of detergent.
3. Shake the bottle for ten seconds with the lid on tightly.
4. Place the jar on the table and let it settle for ten seconds.
5. Measure the height of the suds in centimeters from the top of the suds to the base of the jar. The solution in this jar will be used in the next experiment.
Cleaning power:
1. Pour the water from the jar into the plastic bowl and add warm water to a height of 4 cm.
2. Take a saucer and put a thin coat of Crisco on it in the center, so that there is a diameter of 3 cm of grease.
3. Place it face down in the water and leave it for ten seconds.
4. Without rubbing off the grease on the saucer, remove it and measure the diameter of the grease and record it.
(Before doing this, take some of the soapy water and put it into a babyfood jar to a level of 4 cm, shake for ten seconds. Measure the height of the suds. Record the results.) In the same bowl, put a plate that has a light coat of grease in the center, and wash it off. Dry the dish and repeat the process 25 times. After washing the dishes, take some of the water in the babyfood jar and record the height of the suds after shaking it for ten seconds.
Test for acids and bases: To test for any acid or base in the detergent that might irritate the hands.
1. Take a piece of pH paper and dip it half way into the detergent and water solution.
2. Record the pH of the solution.
Dry leaf Moisturizing:
1. Take a dry leaf and put a few drops of detergent on it.
2. Rub in the detergent and see if part of the leaf can become moist enough to fold without cracking.
Cost per ounce:
1. Using the total cost of the bottle of detergent and the volume listed on the container, determine the cost per ounce of detergent.
BAR SOAPS
Lasting power in water:
1. Using an eyedropper, drop 50 drops of warm water on the soap
2. measure, in centimeters , the indentation in the soap.
Leaving film:
1. Take some soap and wash your hands in the plastic bowl.
2. Take a piece of glass and dip a corner into the water and see if there is some film on the glass.
Perform pH paper test on the soap.
1. Rub a piece of pH paper on the soap.
2. Record the pH of the soap.
Cleaning:
1. Put a drop oil on a piece of scrap cloth.
2. See if you can wash it out with the soap.
Cleaning hands:
1. Put some dirt on your hands and rub it in to your skin.
2. Wash the hands for 15 seconds
3. Record how clean your hands are.
4. Perform the same experiment, except use a little grease on the hands.
5. If there is oil, perform the experiment once more with the oil.
Personal choice: Try the different soaps and rate each from 1-10 based on
"feel after rinsing."
Cost per ounce:
1. Using the total cost of the bottle of detergent and the volume listed on the container, determine the cost per ounce of detergent.
Science CAP 2009 Testing Soaps.doc