The compounds of Tantalum

1. Tantalum Oxide: the most valuable application of tantalum oxide is Tantalum Pentoxide, the chemical formular of it is Ta2O5 . Tantalum Pentoxide is a kind of white powder, it is tasteless and odorless, the proportion of it is 8.71 g/cm3, the melting point of it is 1870 ℃. With obvious acidic, it is insoluble in water, and also insoluble in most of the acid and alkali, but it can slowly dissolve in hydrofluoric acid and peroxyacetic acid, with alkali fusion, generate Tantalate.
The performance of other Tantalum Oxide is instability at a lower price. The main suboxide of Tantalum TaO2 is a kind of brown powder, and insoluble in acid, and when heated in air into Ta2O5, with electrical conductivity.
2. Tantalum Halide: TaCl5 is a kind of yellow powder, the melting point of it is 220 ℃, the boiling point of it is 223 ℃ to 239 ℃, the proportion of it is 3.68 g/cm3. It is volatile, with strong moisture absorption, easy to parse out the white water hydroxide precipitation. In addition to high value TaCl5, the low value of Tantalum Chloride has TaCl4, TaCl3, TaCl2, and they are all volatiles.
3. Tantalum Carbide: there are mainly two kinds of Tantalum Carbide of Tantalum: TaC and Ta2C . TaC is a kind of dark brown powder, the melting point of it is 3880 ℃, the boiling point of it is 5500 ℃, and the density is 14.4 g/cm3, has good chemical stability, can only be dissolved in a mixed solution of nitric acid and hydrofluoric acid. When under 1000 to 1100 ℃, Tantalum Carbide is not easy oxidized in the air. In nitrogen or ammonia effect, it is easy for it to generate nitride.
4. Tantalum Hydride: at a room temperature in air, the Tantalum Hydride is stable. And under a high vacuum is heating to 1000 ℃ to 1200 ℃, decomposition of hydrogen. And when the temperature is under 350 ℃, there is almost no reaction between Tantalum and Hydrogen, the reaction speed grows with the increase of temperature. And the solubility of Hydrogen in Tantalum decreases with the increase of the temperature.
5. Tantalum Nitride: there are three kinds of Tantalum Nitride: TaN, Ta2N, Ta2N5. TaN is a kind of gray powder with blue, the melting point of it is 2980 ℃ to 3090 ℃, the density of it is 14.4 g/cm3. It is insoluble in nitric acid, hydrofluoric acid and sulfuric acid, but soluble in heat alkaline solution and releasing ammonia or nitrogen.
6. Tantalum Boride: there are two kinds of Tantalum Boride: TaB and TaB2, the density of TaB is 14.0 g/cm3. The melting point of TaB2 is 3200 ℃, and the density of it is 11.7g/cm3, it won’t eroded by hydrochloric acid and aqua regia, but can be decompose slowly by hot sulphuric acid and hydrofluoric acid.
7. Tantalum Selenate: the Tantalum Selenate is TaSe2.
8. Tantalum Silicone: the main silicide of Tantalum is TaSi2, and also some other compounds, such as Ta2Si, Ta5Si3. The melting point of TaSi2 is 2200 ℃, and the density of it is 8.83g/cm3. It cannot be mineral acid erosion, but can be decomposed by hydrofluoric acid, and can be completely decomposed in molten Na2CO3 and NaOH.
9. Tantalate: the most important Tantalate is Potassium and Sodium.
10. Tantalum organic complex compound: the main Tantalum organic complex compound is Tannic acid compounds, the color of it is lemon yellow, and will be precipitated from acidic solution after boiling.
11. Tantalum Alkoxide: pentavalent Tantalum Alkoxide is highly volatile, these can be distilled without decomposition at the 6.67 to 1333 Pa pressure. And the boiling point of Tantalum Alkoxide can be affected by the chain length.