What's in Deionized Water?

What is deionized water? Does DI water contains no ions in absolute terms: even the H+ and OH- ions of water?
- clifton (age 60)
Antigua and Barbuda

You can get rid of the other ions but not the H⁺ and OH^-. Even if somehow water were prepared with no ions at all, within an extremely short period of time a certain fraction of the molecules would fall apart to form H⁺ and OH^- ions. Afterwards, the rate of new ions forming would be about equal to the rate of old ions combining to form molecules. It's in this equilibrium state that the concentrations of H⁺ and OH^- are 10^-7 molar, at room temperature.

Mike W.

(published on 03/22/2012)