1. Write an equation showing how excess chlorosulfonic acid is decomposed in water.
2. In the preparation of sulfanilamide, why was aqueous sodium bicarbonate, rather than aqueous sodium hydroxide, used to neutralize the solution in the final step?
1. Chlorosulfonic acid aggressively with water to form hydrogen chloride and sulfuric acid. The equation for this reaction is written as:
`ClSO_3 H + H_2 O -> HCl + H_2SO_4`
2. The most common preparation of sulfanilamide is through the acetanilide route treated with chlorosulfonic acid, ammonia and HCl. The usual reagent for neutralizing the solution is the use of sodium bicarbonate. The neutralization of the solution requires slow addition of the weak base in order to isolate the sulfanilamide effectively. The use of strong bases such as sodium hydroxide (NaOH) can ruin the entire solution and may lead to precipitation.