LiAlH4 vs NaBH4

I`m going to placing an order soon for further stock.

is there much of a difference between LiAlH4 and NaBH4?
the Borohydride seems to be generaly a more stable (less risky) chem to store/use, and that`s always a good thing.
but are there any chemical advantages between one or the other?
they both seem to do more or less the same job.

so I`de like your opinions/advice before I make my choice.

Thanks each

edit: also, what conc of HF(aq) is the most frequently used in general chemistry?
for instance Dillute (38%) nitric acid I get through more than my conc stuff.

[Edited on 11-11-2006 by YT2095]

by,"More or less" seem to do the same job (probably badly worded on my part) I meant as powerfull Reductors.

these 2 were reccomended to me as agents to decarboxylate benzoic acid.
I`m all for keeping the risk factor here as low as possible also, However I Am now curious more than before, what the difference is betwen these 2 agents for such operations?

and you`re quite right, I don`t exactly know too much about these as I`ve never used either of them Yet.
that`s why I`m asking

in that case then, I don`t want it around here at all
my days of enjoying that sort of thing are long gone!

Nicodem, yeah, I was told it would work, although I`ve long since forgoten the source, I do have the note written down here with me, however after what I`ve just read, the BoroHydride seems to be the chem of choice regardless.

I knew asking you guys First would be the right thing to do

I think you meant that LiAlH4 would reduce benzoic to phenol, not decarboxylate. I have never used LiAlH4(yet) but have heard many horror stories about it. On the other hand there are many organic reductions which will only proceed with LiAlH4 and not with NaBH4. Reducing benzoic acid to phenol is one of those.

Unfortunatly Woelen, the good inorganic reducers do not carry over as well to organic as one would like. There are many organic reductions with zinc, and some with dithionite(but it is a rather novel reducing agent to my knowledge), and there is definatly more literature on the use of borohydride and aluminum hydride in reductions.

I suppose HF could be used at home, if you are using less than 5% solutions of it and have a tube of Ca-gluconate gell in your pocket at all times while working with it. But it is definatly not something I would be comfortable with. Go with making dilute solutions when needed like Woelen said, then you avoid storing the stuff as well. I avoid the stuff as much as possible, even the flourides I have I have not even used yet. I am more comfortable with stuff like Mn2O7

HF

I have had the fun of using both LiAlH4 and NaBH4 in organic lab. I remember that in both cases I treated them with respect as powerful reagents. I accidently spilled a little LiAlH4 over the sink when cleaning up. I remember a surprisingly violent reaction when it hit the water in the sink.

HF is the active ingredient in an etchant for glass sold in craft shops. It is somewhat surprising that this is available to the general public in today's litigious climate.

Edit: When I checked my notebook I see that I have not used LiAlH4. The chemical that reacted violently in the sink was AlCl3 I believe.

[Edited on 13-11-2006 by Magpie]

Thanks each

I`ll stick to the Borohydride and the KF salt, the plan is work through my AS and A2 chemistry text books stage at a time, Doing the experiments outlined therein, to get a better understanding and hopefully leave no Gaps in knowledge (I have quite a few).
also the fact that the Borohydride is sufficiently powerfull enough to rip the metals from their salts is Ideal, up to yet I`m either Plating out, thermit or displacement reactions with Mg or Zn, this can lead to significant contamination.
the second part of my goal is to collect/extract as many of the elements as possible towards my element collection, mineral shops are a fairly good source of the raw materials and ores (as are beaches on holiday).

as for Conc Nitric vs HF, I have conc nitric here, and it`s never been an ounce of trouble, it`s quite well behaved although I don`t have cause to use it much, I get through about a litre of the 38% stuff every couple of months though (much more usefull).

Well I had a nice long reply all set to go but the forum software decided to crap out on me, so I'll just put up the succinct version.

HF is a nasty chemical and I'm not arguing that. I am simply arguing the mythical proportions to which this chemical is regarded in terms of danger. This is a direct result of HF being used so very infrequently as there are virtually no reactions that require HF and only HF that most people come across. When something isn't used that often people's imaginations begin to work overtime. Again, HF is incredibly nasty and if you don't know what you're doing (which many people don't) you can get seriously hurt. However, hundreds of thousands of people across the world use it daily in their jobs (Glass etchers, refridgerant producers) and they don't seem to have any higher incidence of death and dismembermant than any other chemistry jobs.

Again, if you know what you are doing then it is a perfectly safe compound to work with. If you don't know what you're doing, then you shouldn't be touching it. The same can be said for concentrated acids, many organic compounds, etc. etc.

As for the HF versus HNO3 dangers, when you've seen an entire stock room fill with NOx vapors thanks to a leaky HNO3 bottle you'd see where I'm coming from. (The entire room was filled with the vapors and there was a serious fear that random fires would start breaking out thanks to the strong oxidizing properties of NOx. HF wouldn't have caused that danger).

I had a 500ml plastic bottle of HF in my early teens, I had no idea of it`s dangers in the way I do as an adult, I just simply treated it as any other acid (I actualy found it quite Boring for the most part too).
I`m still here to tell about this, and with no ill effects at all.
to ME conc HNO3 was THE Acid! that was my idea of what an acid "Should" be like (I was only 14).

I guess in That respect I was "lucky"? I knew nothing about its Toxicity at all, it was just AN acid to me, and treated as such.
I still think the idea of using the salt and making it in situ is a little safer though, I`de sooner have to pick up a dropped crystal than a blob of the acid