Analytical Chemistry Question 29
Question: Nitrates form a brown ring when treated with $ HCl/FeSO_4 $ followed by a few drops of cone. $ H_2SO_4 $ . This test depends upon
Options:
A) the reduction of nitrate to nitric oxide
B) the oxidation of nitric oxide to nitrogen dioxide
C) reduction of ferrous sulphate to iron
D) oxidizing action of sulphuric acid
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Reduction of nitrate by $ F{e^{2+}} $ ions. $ N{O^{-}}_3+3F{e^{2+}}+4{H^{+}}\to \underset{\begin{smallmatrix} Nitric \\ oxide \end{smallmatrix}}{\mathop{NO}}+3F{e^{3+}}+2H_2O $
$ F{e^{2+}}+NO+5H_2O\to {{[Fe{{(H_2O)}_5}NO]}^{2+}} $
BETA
