Talk:Perchloric acid

Perchlorates versus chlorates[edit]

"However, it is strange that perchlorates are even weaker oxidizing agents than chlorates."

How is this strange? AIUI, the perchlorate (ClO4) has a net noble gas electron configuration, making it relatively stable; the chlorate (ClO3), has a less stable electron configuration, and is therefore more reactive, despite having fewer oxygen atoms. I plan to remove / change this sentence in the near future if there are no objections. Evand 04:44, 25 Apr 2005 (UTC)

pKa Inconsistencies[edit]

This page lists the pKa of Perchloric acid as -7.00 ... however, the acid dissociation constant page lists it as -10.00. Additionally, the acid dissociation page and main page for Hydrochloric acid list that compound's pKa as -8.00, suggesting that Perchloric acid's pKa on this page might be inaccurate. --gabe 21:07, 22 September 2006 (UTC)[reply]

According to CRC Handbook of Chemistry and Physics, 87th edition the pKa of Perchloric acid is -1.6 (8-14). The same numeric value is given by Lange's Handbook of Chemistry, 15th edition. An older (1985) German Textbook (Hollemann-Wiberg, Lehrbuch der Anorganischen Chemie) states pKa=-10. I will try to get more info on that.--Xenofonos 20:14, 26 October 2007 (UTC)[reply]

Its been years since this issue has been mentioned, but it needs to be resolved. There are currently two different pKa values given for perchloric acid: -8 and -10. Both are sourced, but I have no way of knowing under what circumstances the pKa was measured since they're offline sources. I looked around online and most sources put the pKa as -7.3, -8, or -10. My guess is that they are referring to the pKa values at different temperatures. In the event that a clear answer is not found, then I recommend listing both pKa values together and stating that the pKa is somewhere in between. Obviously this is undesirable; let's try to find out what is causing reports of different pKa values. Explodo-nerd (talk) 03:11, 16 January 2012 (UTC)[reply]

Negative pKa's are generally not very accurate because they come from extrapolations from non-aqueous solvents, theoretical calculations, or who knows where. It is common to find wildly different values being published, and most textbooks just copy the same number over and over without a lot of clarity regarding the origin of the number. So, unless there is a reasonably recent publication that does an explicit, critical analysis of the pKa of perchloric acid and provides solid ground for a recommended value, I think there's not much we can do in terms of choosing the "right" pKa. We can provide more than one value, citing the sources, and let the reader decide. --Itub (talk) 22:49, 16 January 2012 (UTC)[reply]

Other[edit]

the statement "organic material such as cloth or wood" is functionally, nearly useless. i believe but am not certain that sugar polymers, i.e. cellulose are the primary concern, what is the interaction of poly-aromatic hydrocarbons, i.e. naphthalene. what is the interaction of acetylene, experience says that this is not particularly hazardous. User:Figo —Preceding unsigned comment added by 216.21.137.27 (talk) 21:52, 13 May 2008 (UTC)[reply]

No thermochemistry data (delta-H, delta-S, Gibbs)[edit]

please add. — Preceding unsigned comment added by Riventree (talk • contribs) 21:01, 12 July 2012 (UTC)[reply]

References[edit]

A couple of references were appended to the end of the article, but it is unclear to me which, if any, of the statements in the article they are intended to support. So I'm moving them here in case anyone can put them back in the proper place, or could use them to expand the article. -- Ed (Edgar181) 11:24, 30 April 2014 (UTC)[reply]

German patent DE1031288B
US patent US2846383A
Müler, W.; Jönck, P. (1963). "Herstellung von Perchlorsäure durch anodische Oxydation von Chlor". Chemie Ingenieur Technik - CIT. 35 (2): 78. doi:10.1002/cite.330350203.

According to Ullmann's, these reports (a paper and US and German patents) describe the invention of the electrochemical route from chlorine to perchloric acid. I am going to insert them into the article since they are of probable historic importance.--Smokefoot (talk) 11:56, 30 April 2014 (UTC)[reply]

Thank you. -- Ed (Edgar181) 13:08, 30 April 2014 (UTC)[reply]

70% ???[edit]

This may be a silly question, but 70% perchloric acid means what? 70% by weight, by volume, by mole ratio? — Preceding unsigned comment added by 152.2.174.204 (talk) 20:01, 18 February 2016 (UTC)[reply]

Definitely not silly question. I inserted that it is 70% by weight, since I have not heard of %mole ratio and dont think that volume % make sense either.--Smokefoot (talk) 00:05, 19 February 2016 (UTC)[reply]

Explodes when contacts with organics?[edit]

It's widely said that perchloric acid will make an explosion when reacts with organics.And there are also many disasters about perchloric acid explosion.However,if perchloric is so dangerous like this,then who would dare to use it?Or these dangers are exaggerated? 小小小硝酸 (talk) 19:29, 5 October 2018 (UTC)[reply]

It can explode with organic compounds, but it usually does not. --Smokefoot (talk) 20:37, 5 October 2018 (UTC)[reply]