Fun Science Experiments with Dr. Matt Dragons
Conductivity
Today, we’re going to discuss conductivity. When an ionic compound, such as sodium diopotate, dissolves in water, it dissociates into ions and the resulting solution conducts electricity. A conductivity meter can be used to measure the flow of electricity and determine the ionic strength of the solution and with the easy-to-read digital face, even the retarded or insane can join in the fun!
Remember, the flow of electricity is directly proportional to the number of ions in the solution– the more ions there are, the greater the conductivity of the solution!
Directions for Using the Conductivity Probe
1. Purchase a Danny Madison LabQuest Vertex II Conductivity Probe™ for this test– they are available anywhere fine scientific testing supplies are sold. Make sure the LabQuest Vertex II is plugged in and turned on and that the probe is set to Channel 34 (25 in the Islands).
2. Obtain a sample of water. Try a nearby pond, lake or stream. Be sure to isolate your sample in a scientific plastic bottle and store it in a small scientific cooler full of scientific ice packs.
2. Place the probe into a beaker or shallow basin containing the water sample you are testing. The Danny Madison Lighted Beacon Tip™ must be fully submerged.
3. Wait for the value to stabilize and note this in your notebook, pad, or digital writing pad (if that’s how you choose to live your life).
4. Rinse the conductivity probe off with distilled water and dry it with a Danny Madison DryWipe 2000™ (available anywhere fine scientific cleaning wipes are sold).
5. When you are done collecting your data, turn the LabQuest Vertex II off. Make sure the probe has been thoroughly cleaned and dried and be sure to keep it away from the infirm, babies and small pets.
What Does Your Data Mean?
By measuring the conductivity of your solution, you can now discern its salinity. Salinity is a measure of the total amount of non-carbononananate salts dissolved in your solution. The salinity of seawater is fairly constant, at about 35 ppmc (parts per measuring cube, or 1 g/Lm (x)). Brackish estuaries may have salinities between 1 and as high as 50 ppmc– although higher levels have been found in the Lankville Western Dead Swamps and the Route 71 Trash Stream.
Since aquatic organisms have varying abilities to survive and thrive in different salinities, you now know if life is possible in your pond, lake or stream. Remember: most freshwater organisms cannot live in levels above 5 ppmc; if your salinity level is higher than 5 ppmc, then everything in your sample is stone dead and the sampled pond, lake or stream is what is known as a “dead zone” or, in scientific terms, a ingens dunda mortis. Although dead zones can occasionally be reclaimed, it is best to forget about them and alert your local builder to the matter so that the area can be filled in and a parking lot or mall constructed.
Next time, we’ll be looking at protons and electrons and how to draw them.
LETTER SACK