WHHAATTTT??!

Safely handle all materials! No eating or drinking in the lab!Steps to follow:

1. Obtain a Styrofoam tray to carry items back to your work area2. Upon the tray place a Q tip, toothpick, box of food coloring, plastic cup

with Palmolive dish soap, and Petri dish ½ to ¾ full of solution A,B,C, D or E

3. Work on the tray to minimize clean up and prepare to record pre and post observations (create a data table for your lab group)

4. Place a drop of food coloring at 12 o’clock, 3 o’clock, 6 o’clock, and 9 o’clock (you can use the same or different colors) in your solution. Be sure the colors are spread apart, but not at the edges

5. Use either the toothpick/Q tip to apply a drop of dish detergent to the center of the plate

6. Leave the toothpick/Q tip still in the center for at least 15 seconds7. Observe8. Rinse and dry Petri dish and repeat with a different solution A,B,C, D or E9. Continue to repeat and vary procedure to determine the following:

Determine the following (one per lab group):1. State the Independent variable(s), Dependent variable(s), and Fixed

variable(s).2. Based upon your observations and other lab group observations, rank the

solutions A, B, C, D or E in the order of activity from least to most movement.

3. How does dish detergent operate to clean dishes?4. What is the difference between solutions A, B, C, D or E?5. Based upon your observations and other lab group observations, make an

educated guess as to the exact identity of solution A, B, C, D or E.6. Why was the movement different in the different solutions?

Determine the following (one per lab group):1. State the Independent variable(s) - solution A, B, C, D, or E

Dependent variable(s) – motion/movement, and Fixed variable(s) – dish detergent, food coloring, amounts/volumes

2. Based upon your observations and other lab group observations, rank the solutions A, B, C, D, or E in the order of activity from least to most movement. Answer should be supported by your results

3. How does dish detergent operate to clean dishes? Dish detergent is an amphipathic molecule (both hydrophobic and hydrophilic) it forms a bridge between fat and water enabling non soluble fat to dissolve in water. Basically, the soap cleans the dishes by breaking up the fat/grease and allowing it to flow into the water and down the drain.

Determine the following (one per lab group):4. What is the difference between solutions A, B, C, D and E? Fat content

and water content5. Based upon your observations and other lab group observations, make an

educated guess as to the exact identity of solution A, B, C, D and E.

Determine the following (one per lab group):6. Why was the movement different in the different solutions? The

movement was different in the different solutions due to the proportions of fat and water in the solutionSolution A has 5.0 grams of fat per 240 ml of solutionSolution B has 24 grams of fat per 240 ml of solutionSolution C has 2.5 grams of fat per 240 ml of solutionSolution D has 8.0 grams of fat per 240 ml of solutionSolution E has less than 0.024 grams of fat per 240 ml of solution

Since soap is amphipathic it breaks up the fat/lipid of the milk. The higher the fat content of the milk the more dispersal of this fat when the dish detergent is introduced into the solution. Of course, surface tension is also a factor in the movement of the molecules so even though the higher fat solutions should have more movement the solution may be thicker!