September 3, 2005
The idea, first mix 10 grams of barium carbonate with 10 grams of urea in an iron crucible and heat until molten. It tried to boil over several times and there was a strong smell of ammonia as I heated it with a burner but after 45 minutes or so the boiling had simmered down and the mixture became gooey, since the volume of the mixture had dropped I added an additional 10 grams of urea and 10 more grams of barium carbonate. The mixture again boiled and turned liquid and after some time that too went to a paste, I increased the heat and it again melted and boiled almost over, so I lowered the heat for a while then raised it again, and again, and again, in the end I ended up with a solid bunch of 'rocks' that I allowed to cool and ground into a powder that was off a light orange (due to rust from the crucible likely). I mixed this with carbon powder and covered the crucible and 'put the spurs to it' for 4 hours with only some of the carbon reacting. Carbon reductions with a propane torch are ridiculously slow. In the end my propane gave out before my reaction did so I discontinued heating. No luck... :( However after reading through some posts at sciencemadness I realize that I may have reacted with carbon erroneously, this may only be necessary for the preparation of cyanide from the cyanamide. I will have to do some more research, also I am currently dissolving a ball of zinc in some sulfuric acid as I read zinc cyanate decomposes to the cyanamide at lower temperatures then calcium does. So I have to make some zinc carbonate.
Into a crucible I placed 6 grams of nickel powder prepared from decomposing some nickel oxalate and I added 6 grams of aluminum powder I purchased. I covered the crucible and heated over a propane torch for almost an hour with no results. Growing tired from this and knowing there is an energetic intermetallic reaction to be had I took the torch straight to the top of the powders, they fused at the point of contact and a blinding glow spread out from where the torch contacted and spread through the mass heating the crucible incredibly hot. I covered it and allowed to cool. What I ended up with was a light material fused together full of holes (air holes?). Above is a picture of the nugget I got broken in two. I took a piece of this and added it to some tetrachloroethane in basified water and am currently attempting to decompose this (the reason for making this alloy). A fun little reaction, I wonder if it is a true alloy I formed, there is no powder left in the middle or anything.
I dissolved 30 grams of potassium hydroxide in 125 ml of a methanol/water mix and poured this into 65 grams of hydrazine sulfate to freebase it. Then I allowed it to settle and decanted into a different container. The residue left was added to some water and concentrated sodium hypochlorite solution was added to decompose the remaining hydrazine sulfate and free hydrazine in the waste, as long as there was hydrazine present the mixture would immediately froth and foam upon addition of the hypochlorite, this was a good way to destroy the excess hydrazine, I will distill this at a later date.
September 6, 2005
Distilling Sulfuric Acid (Drain Cleaner)
150 ml black drain cleaner and a pinch of boiling stones were put into a 500 ml RB which was connected to a still head, Liebig (without water running through it), a vacuum adaptor (the off gasses being passed through concentrated NaOH) and into a 100 ml RB at the end. Heating was accomplished with a propane torch. It took quite some time for the sulfuric acid to reach boiling and it didn't help that the boiling stones floated on the top. I jostled the flask from time to time to attempt to prevent flash boiling. However the worry was for naught, this time went much better then my previous attempt under reduced pressure. The boiling was fairly smooth though it is odd that very suddenly white clouds would fill the boiling flask and spill into the condenser. I ran out of propane however before I could distill a significant amount but I did manage to get over 50 ml of exceptionally clear distillate that had awesome dehydrating power, the acid left in the distilling flask was considerably more impure then before, the boiling stones dissolved (What the heck were they?). However it too now posses considerable dehydrating power (I tossed the first 10 ml of distillate as it came over at a low temperature). Overall this procedure is very simple and straight foreword aside form the risk of a catastrophic failure with boiling sulfuric acid (maybe do this over a box of sand?). The purpose of this exercise being to have a reliable grade of sulfuric acid to test the dehydrating of sulfuric acid by metaphosphoric acid.
Heating ammonium phosphate
A beaker (150 ml) was filled half way with commercially available fertilizer that was sold under the pretext of being a high phosphate blend for increasing the color of flowering plants. It was composed of the following >90% ammonium phosphate ~7% potassium nitrate the remainder being EDTA zinc, iron, and manganese. The beaker was placed on a hot plate and in very short order the bottom of the beaker contents liquefied. Then it began to bubble and the volume of the solid began to decrease. During this stage the fumes smelled like something rotten. It was a few minutes later that the whole mass took on the look of half cooked brownie batter and began to spew out ammonia gas. I heated in this way for a while and it became difficult to stir. Eventually I had to remove it from the heat and during the cooling process it cracked. As you can see in the picture above, the zones that received the most heating (It was sharing the hotplate with another reaction) turned a very nice purple and it feathers out to the black/brown color of the fertilizer initially. I would call this a failure, however I was unsure of what to expect. My goal was to prepare meataphosphoric acid, the regular way being to heat diammonium phosphate (NH4)2HPO4 thereby allowing the molecule to loose two molecules of ammonia giving the desired HPO3 formula, however I had the chemical (NH4)3PO4 so where was the hydrogen going to come from? All of the ammonia would be lost in time, it is volatile and the phosphate is notoriously involitile, so would that leave me with a phosphorus oxide? If so, those are volatile correct? I don't know, it was turning into something, I will give it more time and more heat next time and sort it out in the end, unless someone knows a good way to convert ammonium phosphate to diammonium phosphate, I was thinking maybe something using oxalic acid?
Making Phosphoric Acid Via the Wet Process
The 'Wet Process' for making phosphoric acid is a well known way to produce phosphoric acid by treating calcium phosphate (available from pottery suppliers as bone ash) with sulfuric acid, giving the insoluble calcium sulfate we are all familiar with.
Ca3(PO4)2 + 3H2SO4 ---> 3CaSO4 + 2H3PO4
The calcium sulfate being filtered off leaving one with a solution of phosphoric acid that can easily be concentrated by heating to drive off the extra water. So, I measured out 190 ml of concentrated (~16 M) sulfuric acid and added 30 ml of water to the acid [I know, always add acid to water, never the reverse!] then measured out 310 grams of calcium phosphate, so nearly a stoichiometric reaction. I added the calcium phosphate to the sulfuric acid in a 1 L Erlenmeyer flask in portions, the mixture heating up somewhat significantly after each addition. When half of the powder was added the mixture was a thick paste, when it had all been added I was left with a chunky solid.
There was absolutely NO LIQUID! What the heck? So, I added about 150 ml of water to it, then some more and stirred and stirred again and let it sit for 24 hours. When I came back the next day it had settled a little but the bulk of it was still mucky precipitate [Note that these types of precipitates, notably from sulfuric acid and calcium nitrate are notoriously difficult to filter]. So I decanted the liquid through filter paper giving me almost 100 ml of liquid. Then for the fun part, to put 600 ml of sludge through filter paper using a Buchner funnel that held 50 ml or so. I would do a batch, suck it with the vacuum until it looked dry on top then dump it and do the next. It took a few hours, it was messy and not at all fun. Not at all! It smelled too and I got the dilute sulfuric/phosphoric acid on me more then once. So when that was all done I was left with nearly 300 ml of an amber solution (probably colorings from the sulfuric acid).
So I took my hard won liquid and added a stir bar and put it on a hot plate on high. I had to keep adding more of the liquid at first as I had no beakers large enough to hold it all but once it was all added it steadily boiled down giving off organic smelling fumes the whole way (Like something rotting, did they use real bones in this? I thought they only used phosphate rock and 'bone ash' was just a nomenclature thing?) Anyway, my 300 ml of liquid boiled down to 40 ml of black liquid then it started giving off white choking fumes, I guess there is considerable sulfuric acid contamination. What the heck?
Anyway, here is a shot when it was halfway concentrated, I had to stop heating for an hour or so at this point, notice the precipitate I obtained, this is mentioned in all of the texts I have read on the wet process, calcium hydrogen phosphate and such precipitates out at this stage as does any remaining sulfate as calcium sulfate. This was a by the books finding. Never the less, where did all of my acid go, crappy yields and mainly sulfuric acid? What happened with this reaction, did my sulfuric acid just suck, should I just break down and buy phosphoric acid, or should I try again? These questions and more will be answered in the future, until then stay tuned!
September 13, 2005
Dehydrating phosphoric acid
Wow, look at all the copper oxide flaking off my copper crucible after being in use less then 3 hours! Anyway, I bought some Naval Jelly from the hardware store and the stuff was pink, but it has approximately 35 - 40% phosphoric acid with a number of little additives but for the most part water. So I figured I could heat it down to metaphosphoric acid and all would be well with the world. A small amount was first placed into my copper crucible and heated until it boiled for some time then it was removed and the crucible cleaned and inspected, there was no determinable attack on the crucible so I added more of the jelly and heated again. At first it bubbled then stopped and took on a golden/copper color, then it further heated and turned black. Organic components of the mixture decomposing I would guess.
This is what it looked like just before I stopped heating. If you look carefully at the contents of the crucible you can see a strip (to the left at the bottom of the inside) where it looks gray, that is where I moved the rod I was using to stir it past, the phosphoric acid scraped away leaving clean metal underneath and remained where it was, not filling the void. It became very thick and when removed on the rod I was using would solidify to a glass like solid. However the crucible was not noticeably attacked. All in all copper appears to be the most common satisfactory material for the concentration of phosphoric acid to metaphosphoric acid.
Preparation of phosphoric acid from ammonium phosphate
Into the copper crucible was placed a decent amount of ammonium phosphate fertilizer containing small amounts of other chemicals. This was heated with the aid of a propane burner. Quickly the mixture seemed to liquefy and clump together. Ammonia gas was generated and its generation speed increased with temperature. The solid/gooey mixture clumped around the stirring rod and continually gave off ammonia. Then without warning it came to a sudden stop and solidified giving the picture you see above. Then, NOx started wafting off, the nitrates in the fertilizer were attacking the copper. This continued for a short while and then stopped, when the surface was probed it was found underneath the crust had liquefied to a black viscous material. This was heated further eventually dissolving the crust and leaving a placid black liquid. No further gas evolution was observed even with the heat up as high as it would go. The liquid was poured onto a steel plate and allowed to cool. Upon cooling the solid appeared to be metal, it was highly reflective and when broken the center was observed to be glass-like and black. It dissolved in water slowly coloring the water green/orange, contaminated metaphosphoric acid?