An acid with -H0 over 6 is called a superacid. This is an acid that is 106 times
stronger than a 1 molar solution of a strong acid. -H0 for pure sulfuric acid is 12.1, 21.1
for a solution of HF in SbF5, and 26.5 for the combination of HSO3F and SbF5.
Superacids have the ability to remove H- from a hydrocarbon and perform H-D exchange
and C-C bond scission, etc.