# pH: I do not think that word means what you think it means. **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 18, 2010, 10:11pm UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601 "2010-10-18T22:11:14Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Malleus\_Incus\_Stapes](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malleus_incus_stapes/32/3293_2.png) [@Malleus\_Incus\_Stapes](https://boards.straightdope.com/u/Malleus_Incus_Stapes)\ **Post date:** [October 18, 2010, 10:11pm UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/1 "2010-10-18T22:11:14Z")
I have a case of Bic “Mark-It” permanent markers on my desk next to me. They’re great stuff; you can get a nice watercolor effect from them if you do it right. I’ve always bought them individually, but it turns out the pack has extra colors. ANYWAY… there’s the standard checklist on the back about how awesome the product is. Bold colors, long-lasting, marks everything, etc. And the ink is acid-free. More than acid-free, in fact. It says, and I quote, “No added acid, **no measurable pH**.” Okay, I understand what they’re trying to say, but we do have a pH number for true neutral. 7, if I remember my chemistry correctly. Apparently these are (excuse the pun) magic markers, laughing in the face of science and defying all attempts at quantification. Mundane, pointless, and colorful. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [October 18, 2010, 10:24pm UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/2 "2010-10-18T22:24:45Z")
I think having “no pH” is something like a sick person having “no temperature.” ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [October 18, 2010, 11:28pm UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/3 "2010-10-18T23:28:25Z")
No measurable pH? _ **Walk away from the marker. Do it now.** _ I’m surprised it hasn’t burned a hole clear through your desk. ---
**Author:** ![Lightray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lightray/32/391_2.png) [@Lightray](https://boards.straightdope.com/u/Lightray)\ **Post date:** [October 18, 2010, 11:32pm UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/4 "2010-10-18T23:32:10Z")
Eh. To have a measurable pH, it has to be in solution (since pH is a measure of the H+ concentration in solution). Is the ink water-based, or solvent-based? ---
**Author:** ![Malleus\_Incus\_Stapes](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malleus_incus_stapes/32/3293_2.png) [@Malleus\_Incus\_Stapes](https://boards.straightdope.com/u/Malleus_Incus_Stapes)\ **Post date:** [October 19, 2010, 12:46am UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/5 "2010-10-19T00:46:16Z")
Good point. As far as I can tell from the web, it’s alcohol-based. ---
**Author:** ![hougaswd](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@hougaswd](https://boards.straightdope.com/u/hougaswd)\ **Post date:** [October 19, 2010, 1:41am UTC](https://boards.straightdope.com/t/ph-i-do-not-think-that-word-means-what-you-think-it-means/557601/6 "2010-10-19T01:41:03Z")
> [@Lightray](#): > > Eh. To have a measurable pH, it has to be in solution (since pH is a measure of the H+ concentration in solution). > > Is the ink water-based, or solvent-based? Yes, pH is the concentration of H+ ions. pH 7 is neutral. It’s not correct to say something has “no pH” to mean non-acidic. No pH is something more like non-ionic, like gasoline. Picky point: Solvents other than water will dissolve organic acids. It helps a lot if the solvent is polar (having electrical charge separation inside the molecule). The acid’s ability to ionize is limited in these sorts of solvents, but still has a measurable effect. Normal phase chromatography depends on it. Then there are other interesting things like aprotic solvents, and liquid salts. Walt