Sodium metavanadate

Sodium metavanadate is basically an inorganic substance represented by the chemical formula NaVO3. This substance is a sodium salt that contains metavanadate as the counter ion. It is physically present in the form of chunks or powder, with an off-white to pale orange colour. This chemical compound is a colourless, odourless, water-soluble substance having a molecular weight of 121.93gmol-1. The melting point of NaVO3 is 630 °C. Sodium metavanadate is often found in different concentrations. One may explore using high purity types of submicron and nanopowder. It is non-combustible.

Sodium metavanadate (NaVO3) can exist in two crystal modifications, namely the stable monoclinic α-phase and the metastable orthorhombic β-phase, under atmospheric pressure and room temperature conditions. Upon reaching a temperature of 405°C, the metastable β-phase undergoes irreversible transformation into the α-phase.

Sodium metavanadate is frequently used as a starting material for the synthesis of other vanadates. Under acidic conditions, it undergoes a conversion to sodium decavanadate. It is also a precursor of unusual metalates such as [γ-PV2W10O40]5-, [α-PVW11O40]4-, and [β-PV2W10O40]5
Notable compounds include vanadium pentoxide (V2O5), vanadyl sulfate (VOSO4), sodium metavanadate (NaVO3), sodium orthovanadate (NaSVO4), and ammonium vanadate (NH4VO3).

Minerals of Sodium metavanadate

Sodium metavanadate is found in two forms. One of them is metamunirite, which is an anhydrous mineral, and the other is munirite, which is a dihydrate. Both metamunirite and munirite are extremely uncommon minerals. Metamunirite is now only found in vanadium- and uranium-rich sandstone formations in the central-western region of the United States. Munirite, on the other hand, is found in Pakistan and South Africa.

Synthesis of Sodium metavanadate

There are mainly two convenient routes for the preparation of NaVO3.

  1. Reaction of sodium hydroxide with vanadium pentaoxide

It is represented by following general chemical reaction.

2NaOH + V2O5 →2NaVO3 + H2O

To prepare 100.00g of sodium metavanadate dihydrate, we will need 57.57g of vanadium pentoxide and 25.32g of sodium hydroxide.

Combination of small quantity of vanadium pentoxide with vigorous stirring into a flask containing a hot, concentrated solution of sodium hydroxide is carried out. Gradually, the temperature is raised to 100°C and allowed it to remain at that level for a short period of time in order to ensure the reaction is fully completed. Subsequently, separation of the mixture is done by passing it through a filter. To purify the chemical from hydroxide, a substantial quantity of chilled ethanol, acetone, or toluene is added to the solution. The salt will precipitate and settle at the bottom as either fine crystals or powder. Precipitates are purified by filtering it and rinsing it with a little quantity of the identical solvent. Next, the resulting solution is filtered and utilizedfor the purpose of producing crystals.

  1. Reaction of sodium hydroxide with ammonium metavanadate

Following chemical equation is used to represent this reaction.

NaOH + NH4VO3 →NaVO3 + H2O + NH3

To prepare 100.00g of sodium metavanadate dihydrate, we will need 74.06g of ammonium metavanadate and 25.32g of sodium hydroxide.

Mixing of fully saturated solution of sodium hydroxide with tiny portions of heated ammonium metavanadate solution is carried out while heating and stirring the reaction mixture continuously. The commencement of a substantial release of ammonia will occur along with the formation of NaVO3. The emission of ammonia in this process can cause irritation to the eyes and respiratory system. To avoid this, synthesis must be conducted only under a fume hood or in an open environment.

Uses/Application of Sodium metavanadate

Sodium metavanadate finds its applications in various field. Some of them are given below.

  • Sodium metavanadate is a type of vanadium salt that is capable of being utilized as an anti-corrosion agent. It exhibits a high inhibition efficiency of 98% when employed at a concentration of 200 parts per million (ppm). Sodium metavanadate is effective for preserving carbon steel.
  • Sodium metavanadate has various applications, including its use as an ink, fur coloring agent, photography chemical, plant’s life inoculant, corrosion inhibitor in gas as well as mordant and fixer.
  • Vanadium’s health benefits are frequently used in supplements targeting diabetes, heart disease, and cholesterol regulation.
  • Sodium metavanadate is commonly employed as a catalyst, desiccant, dye fixative, and in medical applications such as photography, plant inoculation, and inhibition.
  • It is also utilized in the production of ammonium vanadate and potassium metavanadate.
  • Additionally, sodium metavanadate serves as an analytical reagent and mordant.
  • Sodium metavanadate is utilized in both the photographic and medicinal industries.
  • Additionally, sodium metavanadate is utilized in the production of catalyst and vanadium alloy.
  • Metallic vanadium can be found in several inorganic compounds and six different oxidation states.
  • The main application of this compound is in non-ferrous metals and steels as an alloying reagent.
  • Sodium metavanadate compounds are utilized as catalysts and find uses in chemical, ceramic, and specialty fields.
  • Sodium metavanadate is a beneficial substance that has the property of absorbing moisture from the air.
  • Sodium metavanadate has use in the ceramic and medicinal sectors.
  • Sodium metavanadate is incorporated into fertilizer formulations and is utilized in surface metal remediation processes.
  • The glass and pigments industries, as well as the oil and gas sector, make use of sodium metavanadate.
  • In order to investigate how thermophilic and mesophilic methanogens reduce vanadium, microbial culture medium containing sodium metavanadate have been utilized.
  • For the purpose of creating carbon nanotubes coated with vanadium pentoxide (V205), sodium metavanadate can be utilized as a precursor.
  • Organic coating additives that limit corrosion can also be synthesized using sodium metavanadate. Analytical reagents and mordants both make use of sodium metavanadate.
  • The photographic and pharmaceutical industries have also discovered the utility of sodium metavanadate. The production of vanadium alloy and vanadium catalyst also makes use of sodium metavanadate.
  • It is also employed in the synthesis of organic coating additives that limit corrosion.