Well, just for kicks this weekend I put 350ml of 95% etoh in a 500ml erlenmeyer, put in 1ml 31.45% HCl, then added 40g anhydrous NiCl2 (which I realize is incorrect, I only realized my blunder after addition... damned cannabis!:p). I took a 6"x24" aluminum sheet with a thickness described as "0.025" with no unit and cut many 6" strips about .5-.75" thick, which were then cut into squares and bent into caltrops (opposing edges bent at right angles, two up, two down), washed them in 6N HCl for a few mments before hydrogen evolved, rinsed in dh2o once then began adding them to the erlenmeyer one at a time, 35g total.
Since then it's been about 14 hours, initially the first few caltrops turned completely black almost immediately. Now, I look at it, they are all still evolving H, but the ones that were black lost much of the coating, while no precipitated nickel was observed on the bottom of the flask or in suspension. I can only assume that it redistributed itself. The etoh remains green. I added twice the correct amount of NiCl2, I was just going to pour it off and perform the reaction a second time on new caltrops with the mother liquor. but it hasn't stopped with the bubbling and the thing.
Upon closer inspection, the deposited nickel appears to be a dull, rough, silvery metal coating and not crusty and black like the initial caltrops.
1. Is the dull silvery coating worthy of use? I can't remember which thread I saw it in, but one successful batch was the result of the black and crusty type.
[edit]
chromic - the urushibara nickel cholride solution is green before it has precipitated, but the final catalyst is gray-black, the darker being the prefered as the gray indicates crystalization from too vigourous a precipitation.
Post 251157
(Antibody2: "Re: Preparing Urushibara catalysts", Chemistry Discourse)Damn!
