Question

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

Options

• A dark brown ring is formed at the junction of two solutions.

• Ring is formed due to nitroferrous sulphate complex.

• The brown complex is [Fe(H₂O)₅NO]SO₄.

• Heating the nitrate salt with conc. H₂SO₄ light brown fumes are evolved.

Answer 1

Ring is formed due to nitroferrous sulphate complex.

Explanation:

• The brown ring in the nitrate ion test is actually formed due to the [Fe(H₂O)₅NO]²⁺ complex, not a nitroferrous sulfate complex.
• This complex is a nitrosyl complex in which the NO molecule coordinates with the iron ion.