What are the products formed when sulphur dioxide dissolves in aqueous sodium hydroxide?   

Expert Answers
kjcdb8er eNotes educator| Certified Educator

When dilute sulfur dioxide is absorbed into aqueous alkaline solutions, the following three reactions among others should be considered:

SO2 + H2O <--> H+ + HSO3O-

HSO3 - <--> H+ + SO3 ^(-2)

 

In sodium hydroxide, the following compounds are also produced:

SO2 + NaOH(aq) <--> SO3 ^(-2) + Na+ + H+

SO2 + 2NaOH(aq) <--> Na2SO3 + H2O

SO2 + NaOH(aq) <--> NaHSO3