What chemical reactions will occur with titanium?

Titanium can react with many elements and compounds at higher temperatures. Various elements can be divided into four categories according to their different reactions with titanium:
The first category: halogen and oxygen group elements and titanium form covalent bond and ionic bond compounds;
The second category: transition elements, hydrogen, beryllium, boron, carbon and nitrogen elements form intermetallic compounds and finite solid solutions with titanium;
The third category: zirconium, hafnium, vanadium, chromium, scandium and titanium form an infinite solid solution;
The fourth category: inert gases, alkali metals, alkaline earth metals, rare earth elements (except scandium), actinium, thorium, etc. do not react or basically do not react with titanium. It reacts with the compound HF and fluoride hydrogen fluoride gas to produce TiF4 when heated. The reaction formula is
Ti+4HF=TiF4+2H2+135.0kcal
The non-aqueous hydrogen fluoride liquid can form a dense titanium tetrafluoride film on the titanium surface, which can prevent HF from immersing into the titanium. Hydrofluoric acid is the strongest solvent for titanium. Even hydrofluoric acid with a concentration of 1% can react violently with titanium:
2Ti+6HF=2TiF3+3H2
Anhydrous fluoride and its aqueous solution do not react with titanium at low temperatures, only the fluoride that melts at high temperatures reacts significantly with titanium. HCl and chloride hydrogen chloride gas can corrode metal titanium, and dry hydrogen chloride reacts with titanium to form TiCl4 at >300℃:
Ti+4HCl=TiCl4+2H2+94.75kcal
Hydrochloric acid with a concentration of <5% will not react with titanium at room temperature, and 20% hydrochloric acid will react with titanium at room temperature to produce purple TiCl3:
2Ti+6HCl=2TiCl3+3H2
When the temperature is high, even dilute hydrochloric acid will corrode titanium. Various anhydrous chlorides, such as magnesium, manganese, iron, nickel, copper, zinc, mercury, tin, calcium, sodium, barium and NH4+ ions and their aqueous solutions, do not react with titanium. High Purity Titanium is in these chlorides Has good stability. Sulfuric acid and titanium hydrogen sulfide have obvious reactions with 5% sulfuric acid. At room temperature, about 40% sulfuric acid has the fastest corrosion rate on titanium. When the concentration is greater than 40%, the corrosion rate becomes slower when the concentration reaches 60%, 80% Reached the fastest. Heating dilute acid or 50% concentrated sulfuric acid can react with titanium to form titanium sulfate:
Ti+H2SO4=TiSO4+H2
2Ti+3H2SO4=Ti2(SO4)3+3H2
The heated concentrated sulfuric acid can be reduced by titanium to generate SO2:
2Ti+6H2SO4=Ti2(SO4)3+3SO2+6H2O+202 kcal
Titanium reacts with hydrogen sulfide at room temperature to form a protective film on its surface, which can prevent further reaction of hydrogen sulfide with titanium. But at high temperature, hydrogen sulfide reacts with titanium to produce hydrogen:
Ti+H2S=TiS+H2+70 kcal
The powdered titanium reacts with hydrogen sulfide to form titanium sulfide at 600°C. The reaction product is mainly TiS at 900°C and Ti2S3 at 1200°C. The dense and smooth surface of nitric acid and aqua regia titanium has good stability to nitric acid. This is because nitric acid can quickly form a strong oxide film on the surface of titanium, but the surface is rough, especially sponge titanium or powder titanium. Second, hot dilute nitric acid reacts:
3Ti+4HNO3+4H2O=3H4TiO4+4NO
3Ti+4HNO3+H2O=3H2TiO3+4NO
Concentrated nitric acid above 70℃ can also react with titanium:
Ti+8HNO3=Ti(NO3)4+4NO2+4H2O
At room temperature, titanium does not react with aqua regia. When the temperature is high, titanium can react with aqua regia to generate TiCl2. Ti+8HNO3=Ti(NO3)4+4NO2+4H2O ⑾ In summary, the properties of titanium are closely related to temperature, its existence form, and purity. The dense metallic titanium is quite stable in nature, but powdered titanium can cause spontaneous combustion in the air. The presence of impurities in titanium significantly affects the physical, chemical, mechanical and corrosion resistance of titanium. In particular, some interstitial impurities can distort the titanium lattice and affect various properties of titanium. The chemical activity of titanium at room temperature is very small, and it can react with a few substances such as hydrofluoric acid, but the activity of titanium increases rapidly when the temperature increases, especially at high temperatures, titanium can react violently with many substances. The smelting process of titanium is generally carried out at a high temperature above 800°C, so it must be operated in a vacuum or under the protection of an inert atmosphere. The physical properties of metallic titanium Titanium (Ti) is a gray metal. The atomic number is 22 and the relative atomic mass is 47.87. The arrangement of extranuclear electrons in the sublayer is 1S2 2S2 2P6 3S2 3P6 3d2 4S2. Metal mobility is between magnesium and aluminum, and it is not stable at room temperature. Therefore, it only exists in a chemical state in nature. Common titanium compounds include ilmenite (FeTiO3) and rutile (TiO2). Titanium has a relatively high content in the earth's crust, ranking ninth, reaching 5600ppm, which is converted into a percentage of 0.56%. The density of pure titanium is 4.54×103kg/m3, the molar volume is 10.54cm3/mol, the hardness is poor, and the Mohs hardness is only about 4, so it has good ductility. Titanium has good thermal stability, with a melting point of 1660±10°C and a boiling point of 3287°C. The chemical properties of titanium metal The reduction ability of titanium metal is extremely strong in a high temperature environment. It can combine with oxygen, carbon, nitrogen and many other elements, and it can also deprive oxygen from some metal oxides (such as alumina). Titanium combines with oxygen at room temperature to form an extremely thin and dense oxide film. This oxide film does not react with nitric acid, dilute sulfuric acid, dilute hydrochloric acid, and the king of acids-aqua regia at room temperature. It reacts with hydrofluoric acid, concentrated hydrochloric acid, and concentrated sulfuric acid.
Titanium is corrosion-resistant, so it is often used in the chemical industry. In the past, stainless steel was used for the parts containing hot nitric acid in chemical reactors. Stainless steel is also afraid of the strong corrosive-hot nitric acid. This kind of parts must be replaced every six months. Titanium is used to make these parts, although the cost is more expensive than stainless steel parts, but it can be used continuously for five years, but it is much more cost-effective to calculate.
In electrochemistry, titanium is a one-way valve metal with very negative potential, and it is usually impossible to use titanium as an anode for decomposition.
The biggest disadvantage of titanium is that it is difficult to extract. The main reason is that titanium has a strong ability to combine with oxygen, carbon, nitrogen and many other elements at high temperatures. Therefore, whether in smelting or casting, people are careful to prevent these elements from "invading" titanium. When smelting titanium, air and water are of course strictly forbidden to approach. Even the alumina crucible commonly used in metallurgy is also forbidden to use, because titanium will deprive the alumina of oxygen. People use magnesium and titanium tetrachloride to react in an inert gas-helium or argon to refine titanium.
People take advantage of the extremely strong chemical ability of titanium at high temperatures. During steelmaking, nitrogen is easily dissolved in molten steel. When the steel ingot is cooled, bubbles are formed in the steel ingot, which affects the quality of steel. Therefore, the steel workers add titanium metal to the molten steel to combine with nitriding to become slag-titanium nitride, which floats on the surface of the molten steel, so that the steel ingot is relatively pure.
When a supersonic aircraft is flying, the temperature of its wings can reach 500°C. If a relatively heat-resistant aluminum alloy is used to make the wing, one to two or three hundred degrees will be overwhelming. There must be a light, tough, and high-temperature resistant material to replace the aluminum alloy, and titanium can meet these requirements. Titanium can withstand the test of more than one hundred degrees below zero. At this low temperature, titanium still has good toughness without being brittle.
Utilizing the strong absorption power of titanium and zirconium to air, the air can be removed, creating a vacuum. For example, a vacuum pump made of titanium can pump air to only one part of ten trillion.