Nitric acid acts upon copper
From Biocrawler, the free encyclopedia.
Nitric acid acts upon copper is a phrase used in an old chemistry textbook, and more commonly known, one that was read by Ira Remsen. It prompted him to carry out an experiment, his description of which is often repeated in modern chemistry texts on the importance of experimentation and attending lab class.
Remsen's experiment
While reading a text book of chemistry, I came upon the statement, "nitric acid acts upon copper." I was getting tired of reading such absurd stuff and I determined to see what this meant. Copper was more or less familiar to me, for copper cents were then in use. I had seen a bottle marked "nitric acid" on a table in the doctors office where I was then 'doing time'! I did not know its peculiarities, but I was getting on and likely to learn. The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words "act upon" meant. Then the statement "nitric acid acts upon copper", would be something more than mere words. All was still. In the interest of knowledge I was even willing to sacrifice one of the few copper cents then in my possession. I put one of them on the table; opened the bottle marked "nitric acid"; poured some of the liquid on the copper; and prepared to make an observation. But what was this wonderful thing which I beheld? The cent was already changed, and it was no small change either. A greenish blue liquid foamed and fumed over the cent and over the table. The air in the neighborhood of the performance became colored dark red. A great cloud arose: This was disagreeable and suffocating — how should I stop this? I tried to get rid of the objectionable mess by picking it up and throwing it out the window, which I had meanwhile opened. I learned another fact — nitric acid not only acts upon copper but it acts upon fingers. The pain led to another unpremeditated experiment. I drew my fingers across my trousers and another fact was discovered. Nitric acid acts upon trousers. Taking everything into consideration, that was the most impressive experiment, and, relatively, probably the most costly experiment I have ever performed. I tell of it even now with interest. It was a revelation to me. It resulted in a desire on my part to learn more about that remarkable kind of action. Plainly the only way to learn about it was to see its results, to experiment, to work in a laboratory.
Explanation
Adding copper to nitric acid can be written as follows:
Where (s) is solid, (aq) is aqueous (suspended in water), and (g) is gas.
When the nitric acid hit the copper, it generated amongst other things, nitrogen dioxide, a noxious and insidious poison. He was lucky to have only lost 1¢ and some skin off his fingers. Chemistry professors often use this story to highlight the inital wonder of chemistry as well as important safety rules ("Safety in the Laboratory") (http://www.rosepetruck.chem.brown.edu/Chem10-01/Lab1/Chem10_lab1.htm)
External links
- Pictures and video of the reaction (http://www.angelo.edu/faculty/kboudrea/demos/copper_HNO3/Cu_HNO3.htm) Requires RealPlayer)
- Google search for the phrase "Nitric acid acts upon copper" (http://www.google.com/search?hl=en&q=%22Nitric+acid+acts+upon+copper%22&btnG=Google+Search)
