Swartzlander's Science Spot
Adrian Middle School 7-8
Directions for Shampoo lab
Consumer Product Testing -The Shampoo Lab Directions
Once your Lab team is decided, you will turn in your names to the teacher. Anyone undecided will by determined for them.
You will run each of the tests at your lab table at your own pace. RECORD all your data on the draft charts.
Shampoo samples: These are marked A, B, C, D, as we are running blind sample lab tests. Your shampoo should be marked Sample E (and F if you have several). Costs and names of the others will be given to you once you are done testing and have moved to the computer lab.
Note: You can run additional tests or surveys to compliment your lab if you wish. You may wish to write a survey to ask people why they buy a certain shampoo. Do they always buy the same shampoo? Does cost mater? How does the scent (smell) of a shampoo affect their purchase? What do national surveys show? What do hair salons say about kinds of shampoo? Is this different from the general public? How do their answers compare to the general public? Does the type of shampoo people buy vary by age group? What other factors affect the types of shampoos used/purchased? (Extra Credit??? Hint, hint)
1% solution- you will be given a 1% solution of each of the 4 shampoos you are being provided. For your own shampoo you need to make one. Using the distilled water you will add 1 mL of shampoo to 99 mL of water. Stir this carefully. Do not shake it up, as you do not want it to get foamy…yet!
#1- The pH Test
Get a sample of 25 mL each of the 1 % solutions in a test tube. Using the Nspire handhelds measure each one for its pH. Leave the test tubes in the try for the next test as you finish. Since 7 is neutral, the pH closest to 7 will be considered best.
#2 Foam Height
Place your finger over the top of the first test tube, covering it completely and shake the test tube back and forth 10 times, EVENLY. It will be more consistent if one person does all your samples for this experiment. Measure (in cm) the amount of foam each produces.
This will be measured by dropping a marble into a test tube of shampoo and timing how long it takes to reach the bottom of the test tube. The slowest time will be the best because the highest viscosity takes more time and contains less water. (Do you want to pay for water in your shampoo? How does this affect the amount of shampoo you use each day? Does that affect the cost?)
After you are done the with lab work, you will be given a sheet telling the names, prices and number of ounces for each shampoo. You will divide the cost of the shampoo by the number of ounces. The unit will be “cost per ounce”. The cheaper produce is considered best.
To get an overall picture of what shampoo is best, you will rank each of the products from best to worst with 5 being the best and 1 being the worst. You will do this for each test. (If you have 6 shampoos you would make 6 the best…) In the case of a tie, the shampoos each get the same value and the next worst gets the next lower number. For example if A and B tie for best cost, then they will both get a 5 and the next one gets a 3.
You may finish the cost and ranking portion at home or in the computer lab, if needed.