Sciencemadness Discussion Board

Acids and Bases

rollercoaster158 - 22-4-2012 at 08:09

We know that the reaction between an acid and a base can be pretty underwhelming, but the stronger the acid or base, the bigger the reaction. Wanting to go to the extreme, I looked up the most powerful acid and base and here's what I came up with:

Fluoroantimonic Acid - pKa -25
Sodium Amide - pKa 38

Fluoroantimonic acid is stated as the strongest known superacid, but the superbase page on Wikipedia shows no strongest superbase. This is why I looked through them all, and the highest pKa was sodium amide, at 38. They both react "explosively" with water.

We know that we can get sodium amide from chemical suppliers, but fluoroantimonic acid is extremely difficult to synthesize. You need antimony pentachloride and HF gas, both anhydrous because lots of HCl gas is produced when you make antimony pentafluoride. Then one more HF is used to turn the antimony pentafluoride into fluoroantimonic acid.

SbCl5 + 5 HF --> SbF5 + 5 HCl
SbF5 + HF --> HSbF6

So what happens when you add fluoroantimonic acid to sodium amide? An explosion? Lots of fluorine gas? Nothing at all?

So let's fill in this blank:

HSbF6 + NaNH2 --> ____________

Bert - 22-4-2012 at 11:36

Don't know the exact chemistry, but here's video of the reaction:

Fossil - 22-4-2012 at 12:28

A video on how you would prepare this reaction

rollercoaster158 - 22-4-2012 at 14:43

:D Very funny. There's probably a very powerful reaction, but if anyone on this forum has prepared fluoroantimonic acid before, that would be amazing. I throw that out there as a challenge. I couldn't do it, because I don't think I'll ever have access to HF. (unless you know how to make it ;))

AndersHoveland - 22-4-2012 at 22:01

2 HSbF6 + NaNH2 --> NaSbF6 + NH4SbF6

But just remember, just because they are the "strongest" acids and bases does not mean it will be the most energetic acid-base reaction. Other acids and bases fit more molecules within a given volume or for a given weight.

While acids and bases can certainly react to release large quantities of energy, the most energetic reactions are of the oxidation-reduction type.

I would wonder what the reaction between sodium and SO2F2 would be.
2 Na + 4 SO2F2 --> 2 NaSO3F + SOF4 + SOF2 ?
sulfuryl fluoride is a commonly used fumigant for termites
sodium fluorosulfonate and thionyl tetrafluoride

[Edited on 23-4-2012 by AndersHoveland]