“With every vial of success there is always a pinch of madness.”
— Gunther Bearklawth
With wet chemistry, do you need a raincoat, rain boots and umbrella? No, but you will need a lab coat, gloves, goggles, and a bench. You will also need to wear closed-toes shoes, tie back your hair, and equip yourself with a substantial knowledge of survival safety procedures. Add in glassware, thermometers, heaters, mixers, and a plan of action or a chemical protocol, if it exists. You also are likely to need a collaborator so you’re not in the lab alone, just in case. Wet chemistry is also called bench chemistry, because it is done on a bench.
Wet chemistry deals with chemicals in liquid and volatile forms. Most aggressive, corrosive, flammable, and explosive chemicals — such as acids and solvents — exist in a liquid form. Handled with care, they are indispensable for many methods of chemical synthesis and analysis. Compounds in a chemical reaction manipulated as solutions are prepared using polar or nonpolar solvents. Because certain compounds have a preference for a specific solvent or a group of solvents, even the insoluble matter can be often analyzed by solvent extraction. Large compounds can be disassembled into smaller ones for analysis through chemical digestion by acid or alkali.
Roots in Alchemy
Wet chemistry is an original, “classical” form of chemistry, which grew out of alchemy in the 17th century with a hypothesis that matter consists of atoms. This was presented in The Sceptical Chymist, by Irish scientist Robert Boyle (1627-1691). Classical chemistry is one of the original components of experimental science. Here is what Joseph Black, an inventor of the analytical balance, said about it in the 18th century:
Upon the whole, Chymistry is as yet but an opening science […] worthy the attention of the liberal mind. And it must always become more and more so: for though it is only of late, that it has been looked upon in that light, the great progress already made in Chymical knowledge, gives us a pleasant prospect of rich additions to it. The Science is now studied on solid and rational grounds. While our knowledge is imperfect, it is apt to run into error: but Experiment is the thread that will lead us out of the labyrinth.
With the law of Conservation of Mass, formulated at the end of the 18th century by Antoine-Laurent Lavoisier, and the Periodic Table of Elements, set forth by Dmitri Mendeleev in the 19th century, chemical transformations became rooted in theory, which provided a foundation for all modern chemistry. Modern chemistry developed and branched further into inorganic chemistry, organic chemistry, analytical chemistry, clinical chemistry, synthetic chemistry, physical chemistry, radiochemistry, colloidal chemistry, electrochemistry, polymer science, computational chemistry, thermodynamics, material science, biochemistry, and molecular biology, often overlapping and merging with physics, mathematics, and biology.
Wet chemistry remains a big part of inorganic and organic (carbon-based) chemistry branches. It requires good hands, accurate judgment, focus, and attention to detail, as well as a certain disregard for bad smells. Of course, fume hoods in a modern chemistry lab take care of most volatile compounds, but organic chemistry is especially famous for dealing with extremely smelly substances, hence the historical name “aromatic compounds.”
Wet chemistry is used extensively in many qualitative and quantitative methods of analytical chemistry, such as solubility, turbidity, viscosity determination, and many others. Use of ion-selective electrodes and titration methods combine wet chemistry and electrochemistry in pH, salinity, and moisture analysis.
Although the term “wet chemistry” is mostly used to describe a family of laboratory techniques, it is still used in the scientific literature related to chemical synthesis. For a modern example, how about “Wet chemistry route to hydrophobic blue fluorescent nanodiamond,” intended as a “non-toxic quantum dot analogue for biomedical imaging of cellular membranes?” In modern science, many compounds for nanotechnology are synthesized by wet chemistry methods, linking classics to the future.
Image by luchschen/123RF.
Source: Joseph Black, goodreads.com.
Source: “Wet Chemistry Route to Hydrophobic Blue Fluorescent Nanodiamond,” by V.N. Mochalin and Y. Gogotsi, Journal of the American Chemical Society, April 8, 2009. 8;131(13):4594-5. doi:10.1021/ja9004514.