Fuming nitric acid comes in two colors ... The synthesis is pretty straightforward, if a bit dangerous. An excess of sulfuric acid is added to potassium nitrate, and more or less pure nitric ...

Chlorosulfonic acid was first prepared by Williamson1 in 1854 by the action of phosphorus pentachloride on concentrated sulfuric acid and later2 by the direct action of hydrochloric acid on sulfur ...