Reaction1. Reaction of Vanadium

Reaction of vanadium with air

Vanadium metal reacts with excess oxygen, O2, upon heating to form vanadium(V) oxide, V2O5. When prepared in this way, V2O5 is sometimes contamined by other vanadium oxides.

4V(s) + 5O2(g) → 2V2O5(s) [yellow-orange]

Reaction of vanadium with water

The surface of vanadium metal is protected by an oxide layer and does not reacts with water under normal conditions.

Reaction of vanadium with the halogens

Vanadium reacts with fluorine, F2 upon warming to form vanadium(V) fluoride. The other vanadium pentahalides appear not to be known.

2V(s) + 5F2(g) → 2VF5(l) [colourless]

2. Reactions of Niobium Reaction of niobium with air

Niobium does not react with air under normal conditions. The surface of niobium metal is protected by a thin oxide layer.

Reaction of niobium with water

Niobium does not react with water under normal conditions. The surface of niobium metal is protected by a thin oxide layer.

Reaction of niobium with the halogens

Niobium does react with the halogens upon warming to form niobium(V) halides. So, niobium reacts with fluorine, F2, chlorine, Cl2, bromine, I2, and iodine, I2, to form respectively niobium(V) bromide, NbF5, niobium(V) chloride, NbCl5, niobium(V) bromide, NbBr5, and niobium(V) iodide, NbI5.

2Nb(s) + 5F2(g) → NbF5(s) [white]

2Nb(s) + 5Cl2(g) → NbCl5(l) [yellow]

2Nb(s) + 5Br2(g) → NbBr5(s) [orange]

2Nb(s) + 5I2(g) → NbI5(s) [brass coloured]

Reaction of niobium with acids

Niobium appears not to be attacked by many acids at room temperature but does dissolve in hydrofluoric acid, HF, or in a mixture of HF and nitric acid, HNO3.

Reaction of niobium with bases

Niobium metal is largely resistant to attack by molten alkali but will dissolve slowly.

3. Reactions of Tantalum

Reaction of tantalum with air

Tantalum does not react with air under normal conditions. The surface of tantalum metal is protected by a thin oxide layer.

Reaction of tantalum with water

Tantalum does not react with water under normal conditions. The surface of tantalum metal is protected by a thin oxide layer.

Reaction of tantalum with the halogens

Tantalum does react with the halogens upon warming to form tantalum(V) halides. So, tantalum reacts with fluorine, F2, chlorine, Cl2, bromine, I2, and iodine, I2, to form respectively tantalum(V) bromide, TaF5, tantalum(V) chloride, TaCl5, tantalum(V) bromide, TaBr5, and tantalum(V) iodide, TaI5.

2Ta(s) + 5F2(g) → TaF5(s) [white]

2Ta(s) + 5Cl2(g) → TaCl5(l) [white]

2Ta(s) + 5Br2(g) → TaBr5(s) [pale yellow]

2Ta(s) + 5I2(g) → TaI5(s) [black]

Reaction of tantalum with acids

Tantalum appear not to be attacked by many acids at room temperature but does dissolve in hydrofluoric acid, HF, or oleum (a solution of sulphur trioxide, SO3, in sulphuric acid, H2SO4, also known as fuming sulphuric acid).

Reaction of tantalum with bases

Tantalum metal is attacked by molten alkali.

Production 1. Production of Vanadium

Most vanadium is used as an alloy called ferrovanadium as an additive to improve steels. Ferrovanadium is produced directly by reducing a mixture of vanadium oxide, iron oxides and iron in an electric furnace. Vanadium-bearing magnetite iron ore is the main source for the production of vanadium. The vanadium ends up in pig iron produced from vanadium bearing magnetite. During steel production, oxygen is blown into the pig iron, oxidizing the carbon and most of the other impurities, forming slag. Depending on the used ore, the slag contains up to 25% of vanadium.

Vanadium metal is obtained via a multistep process that begins with the roasting of crushed ore with NaCl or Na2CO3 at about 850 °C to give sodium metavanadate (NaVO3). An aqueous extract of this solid is acidified to give "red cake", a polyvanadate salt, which is reduced with calcium metal. As an alternative for small-scale production, vanadium pentoxide is reduced with hydrogen or magnesium. Many other methods are also in use, in all of which vanadium is produced as a byproduct of other processes. Purification of vanadium is possible by the crystal bar process developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. It involves the formation of the metal iodide, in this example vanadium(III) iodide, and the subsequent decomposition to yield pure metal.

2 V + 3 I2 2 VI3

2. Production of Niobium and TantalumNiobium and Tantalum Production is still on a small scale, and the process involves a

variety of techniques and quite complex. Solving alkali from seed (rock) using acid to melarukan metals, which can be separated from one another. The process was originally developed by M. C. Marignac in 1866 where by using the HF tantalum will tend to slightly soluble form K2TaF7, while niobium will dissolve to form K3NbOF5.2H2O (Greenwood and Earnshaw, 1997).

At this time the isolation of niobium and tantalum mostly use liquid-liquid extraction techniques. Simply put, tantalum can be extracted from the solution using methyl isobutyl ketone HF, and increases the acidity of the water so memugkinkan niobium phase to the organic phase extracted into a new (fresh). The metal can be obtained after being converted / modified in the form pentoxide by reduction with the aid Na or C and can also be used electrolysis or melts florida (Greenwood and Earnshaw, 1997).

SAMPE SINI AJA GUST

REAKSI VANADIUM

Reaksi reduksi vanadium (V) oksida menjadi vanadium (IV) oksida.Belerang dioksida di oksidasi menjadi belerang trioksida dengan vanadium(V) oksida. Pada saat proses berlangsung, vanadium(V) oksida di reduksi menjadi vanadium(IV) oksida.

V(IV) dioksida kemudian di oksidasi kembali oleh oksigen.

PEMBUATAN VANADIUM

Produksi komersial berasal dari abu minyak bumi dan merupakan sumber Vanadium yang sangat penting. Kemurnian yang sangat tinggi diperoleh dengan mereduksi vanadium triklorida dengan magnesium atau dengan campuran magnesium-natrium.

Sekarang, kebanyakan logam vanadium dihasilkan dengan mereduksi V2O5 dengan kalsium dalam sebuah tabung bertekanan, proses yang dikembangkan oleh McKenie dan Seybair.

Pembuatan Vanadium(V)  Memanaskan ammonium metavanadat

2NH4VO3(s) →V2O5(s)+ 2NH3(g)+ H2O(l)  

Pembuatan Vanadium(III)Mengalirkan gas H2pada V2O5 V2O5(s)+ 2H2(g) →V2O3(s)+ 2H2O(l)

  Pembuatan Vanadium(IV)

Mereduksi V2O5 dengan menggunakan reduktor SO2  2VO3-+ 8H+ +2e-→2VO2+ + 4H2O

SO2+ 2H2O→SO42- + 4H+ + 2e-

 _________________________________________2VO3

- + SO2+ 4H+ →2VO2++ SO42-+ 4H2O

PEMBUATAN NIOBIUM DAN TANTALUM

Produksi Niobium dan Tantalum masih dalam skala kecil dan prosesnya melibatkan berbagai macam teknik dan cukup kompleks. Pemecahan alkali dari biji (batuan) menggunakan asam yang dapat melarukan logam ini, dimana dapat dipisahkan satu dengan yang lainnya. Proses ini awalnya dikembangkan oleh M. C. Marignac pada tahun 1866 dimana dengan menggunakan HF maka tantalum akan cenderung sedikit larut membentuk  K2TaF7, sedangkan niobium akan larut membentuk K3NbOF5.2H2O (Greenwood and Earnshaw, 1997).

Pada saat ini proses isolasi niobium dan tantalum lebih sering menggunakan teknik ekstraksi cair-cair. Secara sederhana, tantalum dapat diekstrak dari larutan HF menggunakan methyl isobutyl ketone, dan meningkatkan keasaman dari fasa air sehingga memugkinkan niobium untuk terekstrak menuju sejumlah fasa organic yang baru (segar). Logam tersebut dapat diperoleh setelah dikonversi / diubah dalam bentuk pentoksida melalui reduksi dengan bantuan Na atau C dan juga dapat pula digunakan elektrolisis atau meleburkan florida (Greenwood and Earnshaw, 1997).