It was shown that at 140 ° C ( 284 ° F ) , FSO3H-SbF5 will convert methane into the tertiary-butyl carbocation , a reaction that begins with the protonation of methane : CH4 + H + → CH + 5 CH + 5 → CH + 3 + H2 CH + 3 + 3 CH4 → ( CH3 ) 3C + + 3H2 Fluoroantimonic acid , the strongest acid in the system , is 1016 times stronger than 100 % sulfuric acid , and can produce solutions with a H0 down to -28 .
At 140 ° C ( 284 ° F ) , FSO3H-SbF5 will convert methane into the tertiary-butyl carbocation , a reaction that begins with the protonation of methane : CH4 + H + → CH5 + CH5 + → CH3 + + H2 CH3 + + 3 CH4 → ( CH3 ) 3C + + 3H2 The strongest super acid system , fluoroantimonic acid , is a combination of hydrofluoric acid and SbF5 .