Question

Which statement is not true with respect to nitrate ion test?

• A. A dark brown ring is formed at the junction of two solutions
• B. Ring is formed due to nitroferrous sulphate complex
• C. The brown complex is $[Fe(H_2O)_5 (NO)]SO_4$.
• D. Heating the nitrate salt with conc. $H_2SO_4$, light brown fumes are evolved.

Answer 1

Answer: (B)

Ring is formed due to nitroferrous sulphate complex

Answer 2

Brown Ring Test
$NO_3^−+3Fe^{2+}+4H^+ →NO+3Fe^{3+} + 2H_2O$
$[Fe(H2O)6]^{2+} NO → [Fe(H_2O)_5NO]^{2+} H_2O$
Brown ring

So, the correct option is (B): Ring is formed due to nitroferrous sulphate complex.