Possible products from anion analyses [closed]








**Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers.
 
 






---








 **Homework questions** must demonstrate some effort to understand the underlying concepts. For help asking a good homework question, see: [How do I ask homework questions on Chemistry Stack Exchange?](https://chemistry.meta.stackexchange.com/questions/141/how-do-i-ask-homework-questions-on-chemistry-stack-exchange)




Closed 8 years ago.








[Improve this question](/posts/23891/edit) 



What are possible products from these two anion analyses?


1. The nitrite test, reacting diphenylamine with a nitrite:


$$
\ce{(C6H5)2NH + NO2- -> ?}
$$


2. The sulphite test, reacting potassium permanganate with a sulphite:


$$
\ce{KMnO4 + SO3^{2-} -> ?}
$$




1. Under acidic conditions, a blue colour is observed. This results from the formation of N,N'-diphenylbenzidine. In the course of the reaction, diphenylamine is oxidized to a quinoid radical which subsequently adds to another molecule of diphenylamine.
2. Under slightly acidic conditions, bleaching of the solution is observed. Sulfite is oxidized to sulfate while $\ce{MnO4-}$ is reduced to $\ce{Mn^{2+}}$.


 2