ive been looking in TFSE and the reaction of the bees is negative. they say C and alkali nitrate explode on heating. they say on heating alone they end up with the oxide. and they are 100% correct.
it is a matter of technique. yes, the refs give dec of nitrite at its mp, im sure it does. but if done right you can get a decent yield w/o resorting to making nitrite from HNO3, also an option.
for the Pb reduction mentioned elsewhere, the temp is 400-450C. this means stirring is a must. the Pb is melted 1st!
for C: dont heat it so hard and it wont explode! even so, this risk is not worth taking.
i wonder if people are using a very hot direct heat on their failed attempts to make nitrite. i know that careful heating to the mp and visually looking at the reaction help. if at first...give up? of course they dried 1st.
i am unfamiliar with the sodium salt, but the KNO3 is widely sold here and i know that if dried then heated to 425C in a stainless crucible-gently- then quickly cooled a product is formed that gives all the reactions of nitrite.
so its not pure, i know, the Pb method is better for that, and so is reduction of HNO3. but the characteristic cpds from the nitrite have been prepared in acceptable yield easily separated by dist and redist.
also, you dont need C or C and S to make nitrate explode. it will do this on its own if you use a strong heat.
a method i havent tried- H2 and molten nitrate. no gentle bubbling here, its gotta be fast.
the reduction of acid was done long ago in school. hot acid, Cu, hot carbonate soln, blah blah. works but is wasteful of acid.
there is no simple answer
(get it?)
