Preparation of aqua regia

In terms of analysis, this generally refers to a volume ratio of hydrochloric acid to nitric acid of 3:1, with a hydrochloric acid concentration of about 37% and a nitric acid concentration of about 70%.

This post was last edited by Golden Island on 2011-5-29 22:42. It is best to prepare aqua regia in the exact amount required for production. Don’t stock up too much!

Aqua regia, also known as \"king acid\" or \"nitrohydrochloric acid\", is a highly corrosive liquid that emits yellow fumes. It is a mixture of concentrated hydrochloric acid (HCl) and concentrated nitric acid (HNO3); the mixing ratio can be inferred from its name – the character for \"king\" consists of three horizontal lines and one vertical line, indicating that the volume ratio of hydrochloric acid to nitric acid is 3:1. It is one of the few substances capable of dissolving gold (Au), which is also the origin of its name. Aqua regia is generally used in etching processes and various testing and analysis procedures. However, polytetrafluoroethylene, known as the \"king of plastics\", as well as some highly inert pure metals such as tantalum (Ta), are not corroded by aqua regia (along with substances like silver chloride and barium sulfate). Aqua regia decomposes very easily and has a chlorine-like odor; therefore, it must be prepared and used immediately.

It is best to prepare aqua regia as needed, since freshly prepared aqua regia has the highest activity. When preparing aqua regia, one can try adding hydrochloric acid to nitric acid or vice versa; the difference is quite noticeable. Experience is gained over time, so please keep exchanging ideas with each other

Hey there, could you explain the difference between adding hydrochloric acid to nitric acid and adding nitric acid to hydrochloric acid when preparing aqua regia?

On the 7th floor, I’m not sure how to add it; the effect of aqua regia should be the same. But it’s better if you try it yourself to see the differences. That way you’ll know what the distinctions are

Prepared just before use, incorporated into glass products or those lined with PTFE at http://www.yonton.com/product.asp?id=50

Aqua regia is usually used in production to dissolve gold. When dissolving gold in aqua regia, add three parts of hydrochloric acid first; since it is an exothermic reaction, nitric acid (one part in total) must be added in stages, with the temperature carefully controlled to prevent overflow.