The Unmixables: Investigating Immiscible Liquids

Joyce Cohen                    Shakespeare-Elementary School
                               1119 E. 46th Street
                               Chicago IL 60653
                               312-535-1560

Objectives:

Upon completion of this lab activity, the student will
 (1) Develop an understanding of some properties of liquids.
 (2) Develop skills in hypothesizing.
 (3) Discover the immiscible properties of different milks.
 (4) Discover that some liquids form an emulsion.

Materials:

     For each group of four students:
Eyedroppers, food coloring, pie pans, and 1/2 pint cartons of half and half, 2% 
milk, and whipping cream, and Dawn(r) dish soap (the green concoction) and a
1/2 pint container of water.  Nine empty bottles.  Instruction sheet and an 
observation sheet. 
                        
Teaching Strategies:

     This activity can be done in any format, before beginning the project I 
would give some background information, such as: some liquids are immiscible: 
that is, they will not mix completely and permanently with another liquid.  Oil 
and water are two such liquids. 
     In preparation, students are told to determine the roles of each person in 
the group.  If there are more roles and responsibilities than people in the 
groups, some may have more than one assignment.  
    
Equipment/material Gatherer:

     (gets one pan of milk and one pan of water, one towel, one box of food 
      coloring, and one bottle of green concoction.)
   Experimenter
     (drops food coloring and the green concoction into the water and milk as
      consistently as possible; follows suggestions given on this instruction
      page and those of the observers and notetakers.)
   Observer
     (verbally notes what occurs accurately.)
   Recorder
     (jots down all observations and questions as accurately a possible.)
 
The experiment:

     Preliminary procedures: 1. Put the bowls with water and milk next to each 
other; let the liquids settle to stillness.  2. Help the recorder, the one who 
takes notes, before beginning the experiment.

The Experiment, part 1: Adding the food coloring
     3. Conduct the first part of the experiment by dropping food coloring in 
each bowl, trying to be as consistent as possible.  Enjoy and try a variety of 
"drops"!
     4. Complete "The Experiment, part 1: Adding the food coloring" by recording 
what happens.
     5. Complete the observation sheet by generating and recording questions
that come to your mind during this part of the experiment.

The Experiment, part 2: Adding the Green Concoction
     1. Conduct the second part of the experiment by adding one drop of Green
Concoction to the largest food coloring and water "blobs".
     2. Complete observation sheet.
     3. Add more drops of Green Concoction and watch what happens!
     4. Recorder generates and records questions that come to mind during
this part of the experiment.

The Experiment, Conclusion
Complete all information by recording what you've learned about the experiment.

Performance Assessment:
 
We already know that milk contains drops of fat which do not mix with water 
soluble food coloring.  We also know that whenever the dishwashing liquid 
touches the milk a change occurs.  Given this information, what would you do if 
a oil rig breaks down and spills all of it crude oil into Lake Michigan?  
                                                                         
Rubric:

 End of Unit Assessment     
2 points = Answer with Example and Explanation.
1 point = Answer with Example.
0 points = No Answer.