Acid/Base Anhydrides

[budullewraagh]

so i was reading about energetic mixtures of acids and bases, enthalpy change, flash boiling and the like when i decided to think about the anhydrides of such acids and bases.

 

so if we want to consider the most energetic acid/base mixture, our acid will be conc H2SO4. perchloric acid cannot get up to as high concentrations and the fact that it is an oxidizing acid and can also decompose at elevated temperatures is irrelevant, because we are considering just the acid/base reaction. now as for a base, cesium hydroxide would be beastly, and is soluble in 0.25 parts water. thus, 4g CsOH/1g H2O.

 

4(132.9+16+1)/(4(132.9+16+1)+(18))=0.97

so we can get CsOH to 97% conc.

NH3 cannot get near that concentration.

 

anhydrous NH3, on the other hand, is at 100%, but it wouldn't result in the same extreme enthalpy change as 97% CsOH would.

 

this brings up another thought; what about anhydrides?

SO3+NH3 will not react, will they? perhaps they would work H2O+N2+S. anyone know? if not, a water molecule would be useful. i could imagine this fuming liquidy goodness to be a formidable mixture. imagine the enthalpy change from addition of water. first there is the energy release when the components are dissolved, then immediately the strong acid/base reaction.

 

unfortunately, i believe CsOH and SO3 would react to form the bisulfate of cesium.

 

thoughts, anyone?

[jdurg]

Yeah, in anhydrous conditions I just can't fathom any type of reaction between SO3 and NH3. I don't think SO3 is a strong enough oxidizing agent to oxidize the ammonia, and ammonia isn't a strong enough reducing agent to reduce the sulfur trioxide. In an aqueous environment, the water can act as an intermediate and cause the SO3 to form sulfuric acid, like you mentioned above, and the sulfuric acid will then be able to react with the ammonia.

[Bluenoise]

this brings up another thought; what about anhydrides?

SO3+NH3 will not react' date=' will they? perhaps they would work H2O+N2+S. anyone know? if not, a water molecule would be useful. i could imagine this fuming liquidy goodness to be a formidable mixture. imagine the enthalpy change from addition of water. first there is the energy release when the components are dissolved, then immediately the strong acid/base reaction.

[/quote']

 

Yeah it is a pretty cool idea. A serious water destroyer.

 

 

unfortunately' date=' i believe CsOH and SO3 would react to form the bisulfate of cesium.

 

thoughts, anyone?[/quote']

 

I think you're right. CsOH + SO3 ---> HCsSO4

 

CsOH would most likely mimic water in the way it hydrates the SO3