Search results
Results from the WOW.Com Content Network
Melting point: 1,895 °C (3,443 °F; 2,168 K) Boiling point: ... Another method for the synthesis of chromium carbide utilizes chromium oxide, pure aluminum, ...
Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals. The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist. [3] [4]
Chromium(IV) oxide is used to manufacture magnetic tape used in high-performance audio tape and standard audio cassettes. [89] Chromium(III) oxide (Cr 2 O 3) is a metal polish known as green rouge. [90] [91] Chromic acid is a powerful oxidizing agent and is a useful compound for cleaning laboratory glassware of any trace of organic compounds. [92]
Because of the very high melting point of chromium, chromium thermite casting is impractical. Heating with chlorine and carbon yields chromium(III) chloride and carbon monoxide: Cr 2 O 3 + 3 Cl 2 + 3 C → 2 CrCl 3 + 3 CO. Chromates can be formed by the oxidation of chromium(III) oxide and another oxide in a basic environment: 2 Cr 2 O 3 + 4 MO ...
Hafnium carbide is the most refractory binary compound known, with a melting point of 3890 °C. [8] [9] The ternary compound tantalum hafnium carbide has one of the highest melting points of all known compounds (4215 °C). [10] [11] Molybdenum disilicide has a high melting point of 2030 °C and is often used as a heating element.
The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
Tungsten carbide end mills. The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds. [2] These carbides have metallic properties and are refractory.
Chromium(II) oxide (CrO) is an inorganic compound composed of chromium and oxygen. [1] It is a black powder that crystallises in the rock salt structure. [2] Hypophosphites may reduce chromium(III) oxide to chromium(II) oxide: H 3 PO 2 + 2 Cr 2 O 3 → 4 CrO + H 3 PO 4. It is readily oxidized by the atmosphere. CrO is basic, while CrO 3 is ...