Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Dynamin on January 30, 2019, 02:43:16 PM
-
I'm having a b$*%( of a time calibrating my PH meter with those 3 solutions.
I was wondering, would it not be easier to just calibrate my meter by sticking it in some white vinegar, since that is always a 2.4 PH??
Thank in advance
-
This would be not very accurate. Vinigear is naturla product and amounz of acetic acid differs. Zou need a curve not only one point. You have to to know in which range you have to measure.
Acidic solution: calibrate with pH 7 and pH 4 or lower.
alcaline solution: take pH7 and pH 10 or higher.
-
white vinegar, since that is always a 2.4 PH??
It is not.
-
Okay, so I finally have the darn thing calibrated properly. Now I'[ve got another problem.
I've made a topical solution containing vitamins, minerals and amino acids. Whenever I buffer it to PH7, and I then leave it at RT for a few days, the PH is somehow magically gone up to 7.5 or 8.0.
How can that be??
It cant be the PH meter because whenever I test it on the calibration fluid its spot on
-
Carbon dioxide?
-
Carbon dioxide?
CO2 would make the PH go down, not up. Would it not??
I think it might be going up because I have quite a bit of undissolved solids in the solution.
So I guess my next step should be to microfilter them all out
-
I apologize
I misread your post.
You are correct - Aqueous carbon dioxide reacts with water forming carbonic acid.