Colorado Northwestern Community College
Science of Biology
Lab 3 – Slime Time
22 February 2015
Polar solvents dissolve, or pick-up, polar substances and non-polar solvents dissolve, or pick-up, non-polar substances. In the conducted experiment, the polarity of molecules and their properties are explored. The results of using two solvents on both polar and non-polar inks, further verify this to be true. The student conducted the experiment given, using safe lab practices, that found the polarity of two seperate solvents, and it has been shown through experimental results that the hypothesis formed in the beginning of this experiment is true. It has been deducted from this experiment that solvents which dissolve, or pick-up, water soluble inks are polar, while solvents that dissolve, or pick-up, non water soluble inks are non-polar.
In order to determine the polarity of two solvents, slime and silly putty, an experiment is being conducted that will provide data to formulate a conclusion on the matter. This lab will answer whether or not the tested solvents are polar or non-polar, as well as whether the inks used are polar or non-polar. Information was given in the beginning of the lab explaining that only polar solvents will dissolve or pick-up polar ink, and only non-polar solvents will dissolve or pick-up non-polar solvents. Chromatography will be used to verify conclusions made on the polarity of the inks.
The lab provided information as the basis for the experiment. It was provided that polar solvents only pick-up or dissolve polar substances, as well as that nonpolar solvents only pick-up or dissolve nonpolar substances. Also, in the lab introduction, the information examines covalent and ionic bonds teaching that the polarity characteristics of substances are due to their atomic structure and molecular shape. For example:
Water is a polar molecule due to the electrons being shared between the oxygen atom and the two hydrogen atoms. As the electrons are pulled close to the oxygen atom it leaves a slightly positive charge on the outside of the hydrogen atoms, while the other side of the molecule contains a slightly negative charge. The knowledge of the polarity of water is a control within this experiment.
Using the knowledge of polar and non-polar molecules, we can observe the characteristics of the effects of the experiment on the inks, and determine the polarity of the solvents.
Knowing the composition of the Slime being mainly water, the slime will dissolve or pick-up the water soluble inks and the silly putty will pick up the non-water soluble inks.
Materials and Methods
(1) 250 mL Beaker
5 mL 4% Borax Solution
Dry Erase Marker
(1) 10 mL Graduated Cylinder
(1) 100 mL Graduated Cylinder
Filter Paper (Disk)
Filter Paper (Square)
0.5 g Guar Gum
1 Popsicle Stick
Wooden Stir Stick
Uni-ball® Roller Pen
Part 1: Making Slime
1. Weigh out 0.5 g of guar gum into a 250 mL beaker.
2. Measure 50.0 mL of distilled water into a 100 mL graduated cylinder and pour it into the 250 mL beaker that contains the guar gum. 3. Rapidly stir the mixture with a wooden stir stick for three minutes, or until the guar gum is dissolved. 4. Measure 4.00 mL of a 4% Borax solution into a 10 mL graduated cylinder and add it to the guar gum and water. 5. Stir the solution until it becomes slime. This will take a few minutes. If the slime remains too runny, add an additional 1.0 mL of the 4.0% Borax solution and continue to stir until the slime is the slightly runny or gooey. 6. Once you are satisfied with the slime, pour it into your hands. Be sure not to drop any of it on to the floor. 7. Manipulate the slime in your hands. Write down observations made...
Cited: Phelan, Jay. "1-16." In What Is Life, 27. 2nd ed. New York: W.H. Freeman and Company, 2013.
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