Sometimes, the colour observed in Lassaigne’s test for nitrogen is green. It is because

Question

Sometimes, the colour observed in Lassaigne’s test for nitrogen is green. It is because (A) of green colour of ferrous sulphate (B) ferric ferrocyanide is also green (C) of green colour of copper sulphate (D) of excess of Fe3+ ions whose yellow colour makes the blue colour of ferric ferrocyanide to appear green.

Tardigrade Admin · Accepted Answer

Although blue coloured ferric ferrocyanide is formed but due to the presence of yellow coloured Fe3+ salts, the blue colour gives the shade of green.

Q. Sometimes, the colour observed in Lassaigne’s test for nitrogen is green. It is because

of green colour of ferrous sulphate

ferric ferrocyanide is also green

of green colour of copper sulphate

of excess of $F e^{3 +}$ ions whose yellow colour makes the blue colour of ferric ferrocyanide to appear green.

Although blue coloured ferric ferrocyanide is formed but due to the presence of yellow coloured $F e^{3 +}$ salts, the blue colour gives the shade of green.