What's the Conductivity of Gatorade?
Students measure the conductivity of Gatorade.
Students use conductivity meters to measure various salt and water solutions, as indicated by the number of LEDs (light emitting diodes) that illuminate on the meter. Students create calibration curves using known amounts of table salt dissolved in water and their corresponding conductivity readings. Using their calibration curves, students estimate the total equivalent amount of salt contained in Gatorade (or other sports drinks and/or unknown salt solutions). This activity reinforces electrical engineering concepts, such as the relationship between electrical potential, current and resistance, as well as the typical circuitry components that represent these phenomena. The concept of conductors is extended to ions that are dissolved in solution to illustrate why electrolytic solutions support the passage of currents.
Electrical engineers employ the fundamental knowledge of electricity in their work, and our industrial society greatly benefits from the work that they do! The efficient transport of electrons through electrolyte solutions is critical for applications such as fuel cells, water treatment facilities, electrochemical cells and batteries, as well as for the biological functioning of living organisms. In biological systems, electrolytes (among other solutes) are dissolved with various body fluids to enable many processes within organisms. However, over time, the amount of these dissolved solutes become depleted and must be replenished through the ingestion of food. Under times of extreme exertion, such as playing sports for long periods of time, individuals may suffer from dehydration, which is the excessive loss of body fluids (such as water) and electrolytes. As a precaution, athletes commonly ingest sports drinks such as Gatorade to prevent the excessive loss of bodily fluids to prevent the onset of dehydration. Since sports drinks contain different types of electrolytes, this activity is designed to measure the total amount of electrolytes contained in Gatorade, by equating the measurements of Gatorade to solutions of known amounts of sodium chloride.
After this activity, students should be able to:
- Use conductivity to estimate the amount of salt in Gatorade.
- Explain how electricity travels through liquids.