Talk:Carboxylic acid

0.02% deprotonated acetic acid?

I don't know where anyone got this number. From the pKa, it seems that at pH 7 nearly all of it is deprotonated. At [A-]=[H+] I get 0.4% deprotonation. This website http://www.molecularsoft.com/help/acid_and_base-weak_acid_base_dissociation.htm also comes up with the value 0.4%. Am I doing something wrong? Its 0.02% at pH 0 but thats hardly reasonable. —Preceding unsigned comment added by 128.6.22.134 (talk) 17:18, 23 March 2011 (UTC)

For weak acids like acetic acid, the proportion of the acid that's dissociated is a function of the concentration. At one extreme, you can imagine pure acetic acid, in which none of the molecules will be deprotonated (that's not true, really, because it has its own K_autodissociation of 3.5 x 10-15 M, and since the molarity of pure acetic acid is 17M, 3.5e-15/17 = 0.00000000000002% dissociated). And at the other extreme, a single molecule of acetic acid in a large volume (say, a liter) of water, the acetic acid will be 100% deprotonated because the one molecule won't change the pH until the 25th decimal place, and so with a pKa of 4.75, the probability of not being dissociated for that one molecule is less than 1%. --Atemperman (talk) 03:53, 7 August 2013 (UTC)

The lede needs help!

It reads like an upper-level textbook instead of a few-sentence summary accessible to educated laymen. It's fair to expect Wikipedia readers to have some education, but remember that nearly all are laymen. I'd fix it myself if I knew enough to take it on.—PaulTanenbaum (talk) 05:02, 9 March 2014 (UTC)

Good point, I tried to trim the techno talk.--Smokefoot (talk) 15:04, 9 March 2014 (UTC)

The lede lacks trustworthiness.

"A carboxylic acid /ˌkɑrbɒkˈsɪlɪk/ is an organic compound that contains a carboxyl group…"

— Just one?

"…Carboxylic acids occur widely and include the amino acids and acetic acid (as vinegar)." 

— So not just one? Xkit (talk) 22:43, 31 December 2015 (UTC)

Why is (O) in parenthesis?

Would be nice to explain what is implied by the parenthesis in the R-C(O)OH notation. Normally they are used to separate a functional group, particularly if it comes with a repetitions subscript, but neither applies here... I can understand why R-COOH is preferred to R-CO2H, but the parenthesis are confusing... — Preceding unsigned comment added by 12.104.156.31 (talk) 21:52, 20 August 2015 (UTC)

Organic and inorganic chemists (the ones who actually make these things) use RCO₂H. Some use RCOOH, which looks abhorrent to real chemists (and in my book absolutely defines one as an unredeemable dork). Then there is a third sect that tries to go in between and writes RC(O)OH. People using this formula are loathed by the first two groups.

More seriously and to address your real question, RC(O)OH is very explicit and shows the reader that there is no O-O bond, which one could conclude from alternative ways of writing these formulas. It's a matter of taste and tradition. --Smokefoot (talk) 22:34, 20 August 2015 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Carboxylic acid/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Carboxyl group redirects here. Rated "high" as high school/SAT biology content. The article needs a section on biological context, e.g. carboxyl groups on amino acids etc. - tameeria 05:26, 19 February 2007 (UTC)

Last edited at 05:26, 19 February 2007 (UTC). Substituted at 10:52, 29 April 2016 (UTC)

carboxy or carboxyl?

Can anybody tell which is correct, carboxy group or carboxyl group, based on the appropriate definition? In our country, they tell carboxy group is the canonical name that IUPAC defined, but I cannot find the source. Thank you. Wordmasterexpress (talk) 08:06, 15 April 2019 (UTC)