मराठी

Detection of Elements: Lassaigne's Test - Detection of Phosphorus

Advertisements

Topics

Estimated time: 3 minutes
CBSE: Class 12

Key Points: Detection of Phosphorus

Compound is heated with oxidising agent (sodium peroxide) → phosphorus oxidised to phosphate → solution boiled with HNO₃ → then treated with ammonium molybdate [(NH₄)₂MoO₄] + HNO₃ and boiled → canary yellow precipitate of ammonium phosphomolybdate [(NH₄)₃PO₄·12MoO₃] confirms phosphorus.

Na₃PO₄ + 3HNO₃ → H₃PO₄ + 3NaNO₃

\[ \begin{aligned} \mathrm{H}_3\mathrm{PO}_4 + \underset{\substack{\text{Ammonium} \\ \text{molybdate}}}{12(\mathrm{NH}_4)_2\mathrm{MoO}_4} + 21\mathrm{HNO}_3 \longrightarrow{} & \underset{\substack{\text{Ammonium} \\ \text{Phosphomolybdate}}}{(\mathrm{NH}_4)_3\mathrm{PO}_4 \cdot 12\mathrm{MoO}_3} \\ & + 21\mathrm{NH}_4\mathrm{NO}_3 + 12\mathrm{H}_2\mathrm{O} \end{aligned} \]

Advertisements
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×