Girish Mahajan (Editor)

Ammonium metavanadate

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Covid-19
Related compounds  Vanadium pentoxide
Formula  NH4VO3
Density  2.33 g/cm³
Molar mass  116.98 g/mol
Melting point  200 °C
Appearance  white
Ammonium metavanadate httpsuploadwikimediaorgwikipediacommons22

Making ammonium metavanadate used to make mandelin reagent for drug testing


Ammonium metavanadate is the inorganic compound with the formula NH4VO3. It is a white solid, although samples are often yellow owing to impurities of V2O5. It is an important intermediate in the purification of vanadium.

Contents

Synthesis of ammonium metavanadate


Synthesis and structure

The compound is prepared by the addition of ammonium salts to solutions of vanadate, generated by dissolution of V2O5 in base. The compound precipitates as a colorless solid.

It adopts a polymeric structure consisting of chains of [VO3]-, formed as corner-sharing VO4 tetrahedra. These chains are interconnected via hydrogen bonds with ammonium ions.

Uses

Vanadium is often purified from aqueous extracts of slags and ore by selective precipitation of ammonium metavanadate. The material is then roasted to give vanadium pentoxide:

2 NH4VO3 → V2O5 + 2 NH3 + H2O

Other

Vanadates can behave as structural mimics of phosphates, and in this way they exhibit biological activity.

Ammonium metavanadate is used to prepare Mandelin reagent, a qualitative alkaloid test.

References

Ammonium metavanadate Wikipedia


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