Science Buddies: "Ask an Expert"

Hi i would like to know a way to measure electrolytesin drinks. My project is to figure out which drinks have the most electrolytes vs the price. so far i tried this. I took a glass of pineapple jus and a battery tester. The pineapple jus power came up as 24 on the scale. I tried it with water and it was 64 on the scale. Am I measuring electrolytes? if not what am I measuring? and if you have any other ideas for an energy drink science project please tell me. Your answer will be greatly appreciated.

Thanks,

Hi Dave,

It sounds like you're on the right track with your project. Electrolytes increase the conductivity of a solution, which you are monitoring with your battery tester. For a proof of principle, you could prepare a solutions of water and known amounts of salt and measure them with the battery meter. (salt is a good electrolyte) You should see increased conductivity with increased salt concentration.

For a quick explaination see: http://dl.clackamas.cc.or.us/ch105-03/electrol.htm

This includes some more details - or try looking in a chemistry book.
http://www.usm.maine.edu/chy/manuals/11 ... nduct.html

Some things you might want to think about for background information - What is conductivity and how is it measured? Why do electrolytes increase the conductivity of water? What are some common electrolytes found in drinks?

Jennifer