Scientific Method with Snow Polymer

Immediately after hydrating the snow polymer, have students touch the expanded material. It should be slightly warm to the touch as the reaction between the water and the polymer is slightly exothermic. If students touch a sample of snow that was previously expanded (10 minutes or more) they will find it cool to the touch. Question students as to why this might be, (the reason is that the water in the polymer is beginning to evaporate and it takes heat energy for this process to occur).

Have students brainstorm what variables might affect the evaporation rate of the water over a long period of time. Possible variables might be the size of the container it is left in, the shape of the container, the temperature of the room, the humidity of the room, etc.

Students should select ONE of these variables to test how the evaporation rate of the hydrated polymer is affected. All the other possible variables must be kept constant. A sample lab sheet is included for students.

Students should design an experiment based on the variable they select to examine. Each group should have 3 different values to test. For example, if they select the size of the container the snow is kept in, there should be three different containers. Students should be sure that the containers are all made from the same material, are kept in the same area, etc.

After the groups have properly planned their experiment they should begin the data collection stage. Give each group the same amount of expanded snow to use to test their hypothesis. Over the next two weeks have students measure each of their samples, using a balance each day and recording the mass on their data table. This should take very little time, so the remainder of the experiment can be completed for homework.

Upon writing a conclusion, students can be expected to report their findings to the class. This is a wonderful lab activity to give students a basic understanding of the steps involved in the scientific method.

Snow Polymer Lab

In this lab, you and your group will investigate an independent variable to see how it affects a dependent variable. The dependent variable for all groups will be the evaporation rate of the water in the snow polymer.

1. Brainstorm a list of variables you think may be important in changing the rate of evaporation of the water from the snow polymer.

2. Now, with your group, choose only ONE of these variables to be your independent variable. Record:

3. Write your problem: State as, "What is the relationship between (your chosen independent variable) and the rate of water evaporation?"

4. Write your hypothesis (how you think your independent variable may affect the rate of evaporation).

5. ALL the variables you listed in #1 that are NOT your independent variable are your constants. In the space below, please list these variables that you will not allow to change as you conduct your experiment. How will you ensure that each is unchanged?

6. Now discuss and record the actual design of your experiment, listing procedures you plan to follow. You’ll need at least 3 trials of at least 3 different values of your independent variable. Remember to mention keeping the constants and be sure to explain how you will keep your measurements of the dependent variable accurate. Make a step-by-step, numbered rough draft of your general lab procedures in the space below.

7. Design a Data Table to record your measurements of a two-week period.

8. Create a graph to display your data. Be sure to label your x and y axes appropriately.

9. Write a conclusion that summarizes the relationship between each change of the independent variable and the dependent variable. A reasonable explanation of your results should be included.