Fire and Brimstone

Actually, Cecil is wrong. The reaction of sulfur dioxide (SO2, formed by the burning of sulfur in air) does NOT form sulfuric acid (H2SO4) but rather sulfurous acid (H2SO3). To form sulfuric acid, the SO2 is “burned” in the presence of a catalyst to form sulfur trioxide, SO3. This SO3 is then combined with water to form sulfuric acid. (this is slightly simplified). Sulfuric acid is much stronger and nastier than sulfurous acid, but both are nasty in their own right.

The mailbag question being commented on is found here: What’s up with fire and brimstone?

Please note, the Mailbag section is NOT written by Cecil – Cecil doesn’t make mistakes. Also, Cecil gets paid for the columns, not the Mailbag. The Mailbag section is written by the loyal Straight Dope Science Advisory Staff… In this case, 'twas I who wrote the fire and brimstone stuff. The error on sulphuric acid vs sulphrous oxide had already been noted: Valences, but thanks for pointing it out. We will correct the Mailbag entry at some future date.

The Mailbag item has now been corrected; thanks much for your help, markmeir.