Detailed Product Description:
This kit provides the constituents necessary to create 500ml of
Aqua Regia. This is an extremely powerful oxidizing solution prepared
from concentrated Nitric Acid (69% HNO3) and concentrated Hydrochloric
Acid (38% HCL).
It is the only acidic solution that will dissolve the noble metals such as gold,
platinum and rhodium, and will effectively oxidize anything it comes in
contact with.
Uses:
Typically used for removal of stubborn organic residues from laboratory
glassware, or, in semiconductor processing for removal of deposits from inside
of quartz furnace tubes, it is also popular for gold purification.
Background:
Gold is among the so-called “noble metals,” named as such for their lack of
reactivity. Gold will not dissolve in concentrated forms of either nitric acid or
hydrochloric acid by themselves. But mix the two acids together and the
combination of the chloride with an oxidizer becomes a very effective
medium to dissolve gold, platinum, etc.
The colorful name, “aqua regia,” is derived from ancient alchemy. It is from
The Latin for “royal water,” and is believed to have been discovered in
800 AD by the alchemist Abu Musa Jabir ibn Hayyan.
Formulation:
Note that the often quoted ratio of nitric to hydrochloric of 1 to 3 is a
Chemical ratio and not a volumetric ratio of the available acid solutions.
Using the concentrations of the acids provided, the effective volume ratio
is 5.44 parts hydrochloric acid solution to 1 part nitric acid solution.
Aqua regia decays after being mixed, so it must always be made up fresh.
The nitric acid slowly works on the chloride ion, releasing highly toxic
chlorine gas. Also generated is a reddish-orange gas—the also toxic nitrosyl
chloride (NOCl). It is recommended that 1 part H2O be added if the aqua
regia will be stored for any length of time to minimize the generation of
chlorine gas.
Precautions:
This cleaning solution can do severe damage to the eyes, skin, mucous
Membranes and lungs. Extreme caution should be exercised when using
this formulation due to the generation of chlorine gas and nitrous oxides.
Wear butyl gloves (not latex or nitrile exam gloves), eye protection, and a lab coat.
All work must be conducted under a fume hood.
Warning! Do not attempt to store aqua regia in a sealed bottle. The build-up
in chlorine gas pressure will inevitably result in an explosion of the bottle. Only
mix what is needed and dispose of it when your work is complete.
Read and understand all precautions stated in Material Safety Data Sheet
(MSDS, downloadable below) before using this formulation.
Strong irritant to eyes and skin. Dangerous by inhalation. Corrosive to skin
and mucous membranes. Strong oxidizing agent. Dangerous fire risk
when in contact with organic materials.
Click here to download copy of MSDS (Material Safety Data Sheet).
Contents & Packaging:
Constituents come packed in amber glass boston round bottles, sized to
produce 500ml of aqua regia. Contents include 422 ml of hydrochloric acid
and 77 ml of nitric acid. A separate bottle with vented cap is provided for
containment of the resulting mixture. If the full 500ml is required, simply
pour all of the nitric acid into the mixture bottle and follow by the addition
of the total contents of the hydrochloric acid bottle. Generally, however,
much smaller amounts of aqua regia are required and will thus require
measurement.
