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Q & A: What's in deionized water?

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Most recent answer: 03/22/2012
Q:
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
A:
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)

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