Pretty cool, huh? Here's what's going on…
Au (s) + 3 NO3−(aq) + 6 H+(aq) → Au3+(aq) + 3 NO2 (g) + 3 H2O (l)
and then
Au3+(aq) + 4Cl−(aq) → AuCl−4(aq).
Tetrachloroauric acid (AuCl−4(aq)), yum!
Seriously, though, you do not want to drink or even get any of this on you or you'll have a tale to tell of your very own. Speaking of tales, onward.
THE TALE
Max von Laue and James Franck certainly didn't expect that their country would come to be entangled in an anti-semitic frenzy when they won their Nobel Prizes in 1915 and 1925, respectively, but by 1933—when the Nazi's came to power in Germany—the future was writ large upon the wall. Within months of Hitler's ascendance he had the Law for the Restoration of the Professional Civil Service passed in April of 1933 on the very heels of the Enabling Act on March 23, 1933.
Under the Enabling Act neither the consent of the Reichstag nor the signature of the President of the Republic was any longer required for the promulgation of law. The amendment for Hindenburg was thus a matter of political expediency, not of legal necessity.
Wiki
James Franck and Max von Laue, being rather bright fellows, realized that their 6.4 ounce 23 carat gold Nobel Prize medals would not be safe in their possession with Hitler in power. They knew the avaricious Nazi government could and probably would find some pretext to relieve them of the symbols of their genius and hard work. For von Laue it was because he took pains to be a pain in the ass for Hitler's government, for Franck it was because he was, well, he was ein untermensch. So they sent their prized medallions to their friend and colleague
Neils Bohr in Coppenhagen for safe keeping. Sending their medals out of the country, by the way, was also illegal, quite possibly a capital offense and that is where our tale begins.
Though not Jewish, von Laue was a vocal opponent of the Nazi's anti-semitic policies. In particular he articulated an opposition to the previously mentioned Civil Service Law and exercised his caustic wit at every possible occasion even when speaking at high profile events.
von Laue, as chairman of the Deutsche Physikalische Gesellschaft, gave the opening address at the 1933 physics convention. In it, he compared the persecution of Galileo and the oppression of his scientific views on the Solar theory of Copernicus to the then conflict and persecution over the theory of relativity by the proponents of Deutsche Physik, against the work of Einstein, labeled “Jewish physics.”Wiki
Einstein, by the way, surrendered his passport and renounced his citizenship upon his return to Europe from the United States at the German consulate in Belgium at the end of March 1933. By May, Einstein's books were being burned and he was a target for assassination with a $5,000 bounty. Einstein made a wise and prescient decision to not give the Nazis the chance to humiliate or worse the man who was the very personification of 'Jewish physics'.
The physics conference mentioned above was not the only venue where von Laue voiced his palpable distaste for the Nazis. He spoke out again against the regime at a memorial he and Max Planck organized for Fritz Haber after his death. Haber had emigrated rather than work for the Third Reich. Even though he had a special dispensation from the law and even government funding because of his genius and, more importantly, his weapons research he decided to leave the country because he couldn't abide with the racism and disrespect that his fellow Jewish scientists would be forced to endure.
von Laue choose to stand against the injustice and intolerance of the Nazi state at some, though not fatal, expense to his career. He lost the directorship of the Kaiser Wilhelm Institute for Physics to Peter Debye from 1935 to 1939, though he regained the position he inherited from Einstein when Einstein didn't return to Germany in 1933. von Laue remained in Germany at least until he was taken into custody by the Allies and interned in England to prevent the Russian's from doing likewise and returned to Germany in 1946.
That von Laue was an honorable man goes without question. He could have easily gone along and played it safe like so many of his colleagues (Peter Debye, for example), yet he held firm to his ideals. He made the right choice as history would record it, but it was his choice. For his friend and collegue James Franck, however, the situation in Nazi Germany was considerably simpler and simply stated, James Franck was a Jew.
James Franck seems not to have been as politically active as von Laue obviously was. I suspect that the Nobel Prize winning experimental physicist preferred his lab to the intrigues of university politics as his biography doesn't mention much more than his academic accomplishments from his time at the Kaiser Wilhelm Institute and the University of Göttingen, but that's not to say that he was apolitical, nor that he wasn't at the forefront of the some of the most momentous events of his time. Of course, in the end, it may have just been his ancestry that either excluded or inhibited him politically. None the less he was a talented and important contributor to science.
It was the experiments he performed with Gustav Ludwig Hertz from 1912 through 1914 that empirically confirmed Neils Bohr's atomic theory that won Franck and Hertz the Nobel prize in 1925. Later, after he had emigrated, he was an integral member of the Metallurgical Laboratory at the University of Chicago (part of the the Manhattan Project) and chairman of the Committee on Political and Social Problems which authored the The Frank Report, finished in early June of 1945, which recommended against the use of atomic weapons.
When Hitler came to power in 1933 Franck and his family moved to Baltimore to escape the evident and growing anti-semitism of the new German regime. He took a position at Johns Hopkins University for about a year then spent a year in Coppenhagen as a guest lecturer. He returned to Johns Hopkins in 1935 and then took a position at the University of Chicago in 1938 where he remained until his sudden death while visiting Göttingen in 1964 at the age of 81.
Sometime after 1933, Neils Bohr, who worked at the Institute of Theoretical Physics (which he started) in Copenhagen, Denmark received Max von Laue and James Franck's Nobel prize medals. From that time until the German invasion of Denmark and Norway in 1940 the medals were safe in Bohr's custody. You may not know that each recipient's name is engraved on their Nobel Prize medal, so if they had been discovered by the Germans it could have been curtains for von Laue. Although Franck had emigrated to the United States by that time he certainly would have been sentenced in absentia for exporting gold out of Germany. So Bohr was in quite a quandry about what to do with the Nobel medallions. He and George de Hevesy huddled up to figure out what to do. I suspect that that means that the boss, Neils, left it to George to hide the huge coins. Hevesy suggested that they bury them which Bohr didn't like. He knew the Germans would ransack his beloved institution (which they did) and was afraid that the prizes would be found. So Hevesy turned to his discipline, chemistry. He took the two medals and using our recipe above dissolved the medals in aqua regia, put the bottled solution up on the shelf and waited until the Germans left. Sam Kean describes it in his book The Disappearing Spoon.
...When the Nazis ransacked Bohr's institute, they scoured the building for loot or evidence of wrongdoing but left the beaker of orange aqua regia untouched. Hevesy was forced to flee to Stockholm in 1943, but when he returned to his battered laboratory after V-E Day, he found the innocuous beaker undisturbed on a shelf. |
It was a simple matter precipitating out the gold from solution and sending it back to the Swedish Academy in Stockholm to be recast into von Laue and Franck's Nobel medallions. Both von Laue and Franck were re-presented their Nobel medals in 1952.
Below we have my favorite chemistry professor, Dr. Martyn Poliakoff talking about our cook and a bit about our tale as well...
Well, I hope you found this at least mildly amusing and perhaps even informative. I do not want to hear about any of y'all ending up with acid burns, so if you must play with chemicals please be very careful. As always, thanks for taking the time.
What do you think about my Golden Recipe?
Enjoy your Sunday and have some fun!
~palantir