BITSAT2016ChemistryPractical ChemistryActual
Sometimes, the colour observed in Lassaigne's test for nitrogen is green. It is because
Options
- Aof green colour of ferrous sulphate
- Bferric ferrocyanide is also green
- Cof green colour of copper sulphate
- Dof excess of Fe ³⁺ ions whose yellow colour makes the blue colour of ferric ferrocyanide to appear green.
Correct answer
D. of excess of Fe ³⁺ ions whose yellow colour makes the blue colour of ferric ferrocyanide to appear green.
Step-by-step solution
Although blue coloured ferric ferrocyanide is formed but due to the presence of yellow coloured Fe ³⁺ salts, the blue colour gives the shade of green.