5.3 Electrolytes

Joe: For the last time, I’m pretty sure what’s killing the crops is this Brawndo stuff.
Secretary of State: But Brawndo’s got what plants crave. It’s got electrolytes.
Attorney General: So wait a minute. What you’re saying is that you want us to put water on the crops.
Joe: Yes.
Attorney General: Water. Like out the toilet?
Joe: Well, I mean, it doesn’t have to be out of the toilet, but, yeah, that’s the idea.
Secretary of State: But Brawndo’s got what plants crave.
Attorney General: It’s got electrolytes.

Brawndo. It's got electrolytes. [Source](https://www.wired.com/2008/05/nyt-from-silver/)

Figure 5.7: Brawndo. It’s got electrolytes. Source

As noted before, electrolytes (substances that result in ions when dissolved), form electrically conductive solutions. The more ions that are dissolved, the more conductive the solution is. Therefore, conductivity can be used to determine

  1. The real van’t Hoff factor for a solution of some known concentration
  2. The strength of the electrolyte
Electrolyte strength. Figure from [OpenStax](https://openstax.org/books/chemistry-2e/pages/11-2-electrolytes)

Figure 5.8: Electrolyte strength. Figure from OpenStax

Strong electrolytes include:

  1. Strong acids
  2. Strong bases
  3. Ionic compounds that ionize completely (e.g. salts including NaCl, KNO3, MgCl2, CH3COONa)

Weak electrolytes include:

  1. Weak acids
  2. Weak bases


Below is a table of substances. Predict which ones are a strong, weak, or non-electrolyte.

Number Substance Formula
1 Distilled water H2O
2 Tap water H2O
3 Sodium chloride NaCl
4 Sugar
5 Vinegar CH3COOH
6 Hydrochloric acid HCl
7 Sodium hydroxide NaOH
8 Ethanol C2H5OH
9 Barium sulfate BaSO4