Science Buddies: "Ask an Expert"

The Electrolyte Challenge: Orange Juice vs. Gatorade
I have completed the experiment, and am now writing my abstract for the project. However, my results for measuring the electrolytes are all negative decimals. I can't figure out which drink ended up having the most electrolytes. Here are my electrolyte results: Gatorade (-0.025) Tap water (-0.028) Orange Juice (-0.05) Distilled Water (0.00)
Other than the distilled water, which drink had the most electrolytes??

belfry - Are you stating your measurements in terms of conductivity? That is, 1/Resistance. There was some prior reference that the meter connections were reversed in some of the web materials for this experiment. The battery + (red) should be connected to the meter + (red). If you had reverse polarity on the meter, you might indicate negative signed current flow. If you converted resistance to conductance, the negative sign would still be with you. Your measurements might be good except for the polarity.

Rick Marz

Rick Marz,

Thank you very much for the help! I think I understand now, however I have a very limited amount of time to turn in all of my results. Would my measurements still be accurate if I just removed the negative signs?

-Belfry

belfry - I think your readings are good, just get rid of the negative sign. Most inexpensive digital multimeters will read out polarity, the actual measured current is likely accurate. In re-reading your first post it looks like you are showing current in Amperes, (25 to 50 mA for these liquids).

Rick Marz

Rick Marz,
Thank you so much for your help!

-belfry