# PA in chemistry **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [June 14, 2013, 3:32pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991 "2013-06-14T15:32:18Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![GatoRat](https://avatars.discourse-cdn.com/v4/letter/g/f6c823/32.png) [@GatoRat](https://boards.straightdope.com/u/GatoRat)\ **Post date:** [June 14, 2013, 3:32pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/1 "2013-06-14T15:32:18Z")
Or, Pa, is Element 91, Protactinium. [http://en.wikipedia.org/wiki/Protactinium](http://en.wikipedia.org/wiki/Protactinium) [http://chemistry.about.com/od/elementfacts/a/protactinium.htm](http://chemistry.about.com/od/elementfacts/a/protactinium.htm) ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [June 14, 2013, 3:43pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/2 "2013-06-14T15:43:10Z")
column is [http://www.straightdope.com/columns/read/939/in-chemistry-what-do-the-letters-pa-stand-for](http://www.straightdope.com/columns/read/939/in-chemistry-what-do-the-letters-pa-stand-for) only the first letter of an elemental symbol is upper case. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [June 14, 2013, 3:48pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/3 "2013-06-14T15:48:51Z")
As Cecil points out, from the context of the question, clearly the asker is referring to pH. ---
**Author:** ![Outpits](https://avatars.discourse-cdn.com/v4/letter/o/4bbf92/32.png) [@Outpits](https://boards.straightdope.com/u/Outpits)\ **Post date:** [June 14, 2013, 6:18pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/4 "2013-06-14T18:18:02Z")
I thought maybe they were checking the pressure in Pascals (Pa), but just as with the element, both letters of the question were capitalized ---
**Author:** ![sfbiker](https://avatars.discourse-cdn.com/v4/letter/s/67e7ee/32.png) [@sfbiker](https://boards.straightdope.com/u/sfbiker)\ **Post date:** [June 14, 2013, 9:02pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/5 "2013-06-14T21:02:32Z")
> [@johnpost](#): > > column is > > [In chemistry, what do the letters “PA” stand for? - The Straight Dope](http://www.straightdope.com/columns/read/939/in-chemistry-what-do-the-letters-pa-stand-for) > > only the first letter of an elemental symbol is upper case. The original letter writer appears to be relating what he heard, so his sense of capitalization isn’t really relevant – the amateur scientist he’s referring to may have meant “PA”, “Pa”, “pA” or even “pee-aye”, but since the letter writer doesn’t know what the scientist was referring to, he just wrote “PA” in his letter to Cecil. Though I think Cecil’s belief that he misheard and the amateur scientist was saying “pH” makes the most sense. ---
**Author:** ![Slither](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@Slither](https://boards.straightdope.com/u/Slither)\ **Post date:** [June 14, 2013, 10:55pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/6 "2013-06-14T22:55:24Z")
After some thought, I think there’s some misinterpretation going on and its obvious that the question relates in some way to drug manufacturing, as the second response picks up on. However, that response refers to lead acetate, and Cecil rightly points out that “PA” makes no sense for lead acetate. Allow me to refer the curious to a substance known as Phenylacetic acid, known as “PAA”, an organic compound used to make phenylacetone, which is used to make methamphetamine. Given the context of the question that refers to “amateur chemists” (wink wink nudge nudge) and " I’m in jail awaiting transfer to the Texas Department of Corrections", I think a connection to drug manufacturing is likely. _Breaking Bad_ is all the fad these days, so the question is timely. And its not beyond thought that the questioner, being of criminal mind and perhaps not being the sharpest knife in the drawer (he got caught, didn’t he?) misheard “PAA” as “PA”. Or maybe his amateur chemist friends like to take shortcuts and drop the last A. I’m not one of Cecil’s assistants, so I can use Wikipedia: > **[Phenylacetic acid](https://en.wikipedia.org/wiki/Phenylacetic_acid)** > > Phenylacetic acid (PAA; conjugate base phenylacetate), also known by various synonyms, is an organic compound containing a phenyl functional group and a carboxylic acid functional group. It is a white solid with a strong honey-like odor. Endogenously, it is a catabolite of phenylalanine. As a commercial chemical, because it can be used in the illicit production of phenylacetone (used in the manufacture of substituted amphetamines), it is subject to controls in countries including the United State... Enjoy 🙂 ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 15, 2013, 12:33am UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/7 "2013-06-15T00:33:43Z")
And the amateur chemist _certainly_ wasn’t referring to protactinium. ---
**Author:** ![Saltire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saltire/32/553_2.png) [@Saltire](https://boards.straightdope.com/u/Saltire)\ **Post date:** [June 20, 2013, 10:19pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/8 "2013-06-20T22:19:51Z")
I’m no kind of chemist, but it’s possible that both Slither and Cecil were right, in a sense. Since PAA is an acid, one could imagine ‘checking’ it with any of the standard methods of determining pH. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [June 23, 2013, 1:37pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/9 "2013-06-23T13:37:06Z")
> [@](#): > > Since PAA is an acid, one could imagine ‘checking’ it with any of the standard methods of determining pH. Checking the pH of the reaction mixture would be a really lousy way of monitoring the degree of conversion in this case (synthesis of phenylacetone from phenylacetic acid), as acetic acid / acetate ion would also be present, presumably in great excess. Also, p.a. stands for _pro analysi_, the highest purity grade normally available for commercial chemicals (above _puriss._ and _purum_). Not the stuff I’d expect meth cooks to use (well, actually, I suppose meth cooks would use whatever grade they could come by). ---
**Author:** ![ziix](https://avatars.discourse-cdn.com/v4/letter/z/aeb1de/32.png) [@ziix](https://boards.straightdope.com/u/ziix)\ **Post date:** [June 28, 2013, 1:31pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/10 "2013-06-28T13:31:49Z")
Quick google search on lead acetate to verify this responders plea of trust leads to the Lead acetate page of wikipedia which shows two forms of Lead acetate, one “nicknamed” plumbic acetate, which could clearly be abbreviated PA. Whether this is correctly done in chemistry I don’t know but we’re talking about “amateur chemists” who may have little or no formal education. I’m not going to bother getting into how much people like to shorten things in general. > **[Lead acetate](https://en.wikipedia.org/wiki/Lead_acetate)** > > Lead acetate can refer to: ---
**Author:** ![AntiDote5](https://avatars.discourse-cdn.com/v4/letter/a/e99b99/32.png) [@AntiDote5](https://boards.straightdope.com/u/AntiDote5)\ **Post date:** [May 12, 2014, 6:02pm UTC](https://boards.straightdope.com/t/pa-in-chemistry/660991/11 "2014-05-12T18:02:00Z")
> [@Ignotus](#): > > Checking the pH of the reaction mixture would be a really lousy way of monitoring the degree of conversion in this case (synthesis of phenylacetone from phenylacetic acid), as acetic acid / acetate ion would also be present, presumably in great excess. > > Also, p.a. stands for _pro analysi_, the highest purity grade normally available for commercial chemicals (above _puriss._ and _purum_). Not the stuff I’d expect meth cooks to use (well, actually, I suppose meth cooks would use whatever grade they could come by). what da hell cooking meth from phenylacetic acid :eek:… is plastic synthesis, can’t use for crack’in or etc… coz it’s not soluble in water and even thou it’s still hard plastic , that means not for smoke or inject. i think it’s “just for replica only”😃