Why a filter paper dipped in potassium iodide turns brown when brought near HNO3 vapours

Asked by lovemaan5500 | 23rd Oct, 2017, 05:23: PM

Expert Answer:

when filter paper dipped in potassium iodide brought near to HNO3 fumes, they form brown coloured iodine and nitrogen dioxide gas. 
 
2 K I space plus space 4 H N O subscript 3 space rightwards arrow with blank on top I subscript 2 space plus space 2 N O subscript 2 space plus space 2 K N O subscript 3 space plus space 2 H subscript 2 O
 

Answered by Ramandeep | 24th Oct, 2017, 12:14: PM