# How can we use conductivity measurements of water to find hydrogen ion concentration of water?

How can we use conductivity measurements of water to find the hydrogen ion ($\mathrm{H}^+$) concentration in water?

• For the question are you considering that H+ is the only cation? Or is your solution filled with an assortment of cations and anions. Jan 12, 2016 at 11:26
• It is pure water. No other ions are present.
– user102708
Jan 12, 2016 at 13:30
• hmmm...are you allowed just to use the pH and figure from there? Jan 12, 2016 at 16:23
• No, we want to find H+ ion concentration using the conductivity method. We want to find the pH using that.
– user102708
Jan 13, 2016 at 13:55
• Isn't that what a pH meter does? Feb 22, 2019 at 16:41

Okay, this is how I would do it, I would set up cathode and anode to measure the conductivity. I would then compare that to a buffer solution of known ph. If you can't find a buffer solution, see if there is a chart you can find of Hydrogen ion conductivity relationship to pH.(But then you may have to take in temperature of solutions). http://patentimages.storage.googleapis.com/EP0229038A2/imgb0001.png

Such as this, this will give you a relationship which you should be able to figure out from. You do know what "Molar" means? or to figure ppms?

• If you can't find a buffer solution, see if there is a chart you can find of Hydrogen ion conductivity relationship to pH.(But then you may have to take in temperature of solutions).
– user102708
Jan 13, 2016 at 18:47
• Assume you do not have such a chart, you are the first person doing the expt. Buffer conductivity is not only due to H+ ions so you can't compare them directly.
– user102708
Jan 13, 2016 at 18:58
• @OddharakTyagi, I added a chart of conductivity and concentrations. But, I guess you are trying to figure it out from "scratch". My thought would be to work it back from your conductivity test. Look up the formulas, will deal with Ohms, possibly can figure from there. Jan 13, 2016 at 19:19
• Be careful . $H_2$ and $O_2$ will form. Clearly that is outside the scope of Ohm's law. Nov 3, 2019 at 10:10
• How does this differ from a standard pH meter ? Nov 3, 2019 at 10:16