Sciencemadness Discussion Board

Perchloric Acid

Hawkguy - 10-10-2014 at 17:01

I've been thinking of making Perchloric Acid, mostly out of pure interest/ for novelty's sake. The procedure I have found is to add 8.4ml of a 12 M Hydrochloric Acid solution to 12.2g Sodium Perchlorate, leaving Sodium Chloride and Perchloric Acid, both in an aqueous solution. The water first, and then the Perchloric Acid can be distilled out of the mixture. Has anyone attempted this before/ have any advice?

Metacelsus - 10-10-2014 at 18:00

I've made perchloric acid before, distilling sulfuric acid, sodium perchlorate, and water (don't leave this out, or it could explode) under vacuum.

hyfalcon - 10-10-2014 at 19:12

You want to avoid concentrations of perchloric acid greater then 70%. Going over that can cause an explosion.

caterpillar - 12-10-2014 at 05:14

Quote: Originally posted by Hawkguy  
I've been thinking of making Perchloric Acid, mostly out of pure interest/ for novelty's sake. The procedure I have found is to add 8.4ml of a 12 M Hydrochloric Acid solution to 12.2g Sodium Perchlorate, leaving Sodium Chloride and Perchloric Acid, both in an aqueous solution. The water first, and then the Perchloric Acid can be distilled out of the mixture. Has anyone attempted this before/ have any advice?


Excellent. What do you know about dissociation, ions and so on? There will be no Sodium Chloride nor Perchloric Acid in your solution- only anions and cations. And after disstillation you'll get Hydrochloric Acid back- it is much more volatile than Perchloric one.

Metacelsus - 12-10-2014 at 05:36

Well, actually this is a valid way to make perchloric acid. Using a saturated solution of sodium perchlorate, and adding concentrated hydrochloric acid, sodium chloride will precipitate, leaving you with mostly perchloric acid. However, there will still be some chloride left. If you want chloride-free perchloric acid, you must use sulfuric acid (or possibly phosphoric could work too).