July 31, 2004
A procedure that I found for making nickel carbonyl stated that mercury is an excellent catalyst for the formation of the carbonyl. In the preparation they specifically heated a mixture of nickel formate or oxalate with .1g of mercuric oxide until they decomposed followed by running carbon monoxide over them, so I figured a day in the lab would get me up and running on that project. To make mercuric oxide I did some reverse engineering, I went into the chemical dictionary and looked it up, it was made by adding sodium carbonate to a soluble mercury (II) salt. So I figured the nitrate would work since it was easily made. So I heated a test tube of 69% nitric acid to 60C in a water bath and added two drops of mercury. The reaction was vigorous liberating large amounts of NO2 gas but it was over quickly. Afterwards I was left with a yellow/orange solution. I added this to a larger volume of water inside a 250 ml Erlenmeyer flask and put a thermometer adapter in the 24/40 joint in the top. Through this I inserted a pipette with Na2CO3 solution and pumped it in. Then I would take it out to refill it. This was done to prevent spatter from the carbon dioxide produced in the neutralization, because of course mercury compounds are very toxic. Afterwards I ended up with a bright orange/red precipitate, I swirled the flask and rinsed it into a 150 ml beaker then waited for the solid to all settle, I was left with an off yellow solution. I poured this into another beaker and treated it with elemental sulfur, to convert the mercury to the sulfide which is the most environmentally benign form known. I set both of these on a hot plate, the precipitate quickly drying out to give the solid on the left which I promptly put into a sealed container, roughly 1 gram was obtained, my scale only goes down to 1 g and it didn't register but it was probably close. No need making more then I need, this stuff is not good to have around. The remaining solution ended up as a solid precipitate after most of the water was removed, it is currently being stored awaiting disposal.
To make the oxalate I made a saturated solution of nickel chloride and added a large excess of oxalic acid, the solution containing excess oxalic acid as a solid at the bottom in an attempt to push the equilibrium to the somewhat insoluble nickel oxalate:
NiCl2(aq) + HOOCCOOH(aq) ---> Ni(OOC)2(s) + 2HCl(aq)
After everything settled the water was decanted and the precipitate (left bottom) was heated until it turned to a crumbly powder. Yield was roughly 80% theoretical based on nickel chloride, the total conversion inhibited by the acidic environment, it would have been better to use sodium formate to lead to the formation of a neutral salt rather then an acid which would have increased yields.
It was a few weeks later that I took my nickel oxalate out and put it into a 50 ml volumetric flaks and loosely fitted it with a stopper. I put it on my hotplate on high heat and water vapor immediately started to come off it from the hydrate breaking down, condensing in the neck. This also got into the stopper and caused it to occasionally freeze and not let out the vapors inside so I had to manually adjust it on occasion. A black color spread from the hottest part of the bottom to the top, in the end I had what looked like topsoil in the flask, it was very free flowing. The decomposition on a hot plate took roughly 10 minutes over high heat with occasional swirling of the flask contents. Upon exposure to the air the nickel powder did not appear to be pyrophoric but I immediately transferred it to the reaction vessel after decomposition of the oxalate:
Ni(OOC)2(s) --Heat--> Ni(s) + CO2(g)
The nickel powder was used in my second attempt at anhydrous hydrazine in one step on September 27, 2004.
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