2007-04-30 15:42:50 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
pH 7 is perfect neutral water. OH and H ions in balance. lower pH is acidic, higher is basic. in order for this to happen there has to be additional ions to balance, which would not be possible in pure water.
2007-04-30 15:50:11 · answer #1 · answered by lare 7 · 0⤊ 0⤋
7
2007-04-30 22:50:42 · answer #2 · answered by Jake T 1 · 0⤊ 0⤋
You have the basic equilibrium that exists in pure water:
H20 <--> OH- + H30+
As you can see from the equilibrium equation, all the concentrations are the same. This is good. It means there's a relationship! And that means we can know stuff!
You have your equilibrium constant of water, Kw = 1.0 * 10^-14. That Kw = [H30+]*[OH-] as well. Since the H30+ and OH- concentrations are the same, you can plug an 'x' in for each and solve.
10^-14 = x^2
10^-7 = x
Basically, the concentrations of each are 10^-7 M. The pH is calculated as the -log([H30+]), in this case being -log(10^-7), which is -(-7) = 7.
This is usually expected to be common knowledge as well, so remember it.
2007-04-30 22:52:01 · answer #3 · answered by atmtarzy 2 · 0⤊ 0⤋
The ph of pure water, distilled water, at any temperature is 0.
2007-04-30 22:47:23 · answer #4 · answered by rek_obs 2 · 0⤊ 0⤋
it should be 7 .. but since water grabs the ions out of the air ... it will probably be more acidic ..
for example .. if you get a bottle of water and open it and then leave it out for a day or so .. the ph will change
2007-04-30 22:48:21 · answer #5 · answered by CoachAutumn 4 · 0⤊ 0⤋