Search results
Results From The WOW.Com Content Network
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
The Pourbaix diagram for chromium in pure water, perchloric acid, or sodium hydroxide [1] [2] 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 ...
Chromium also has two metastable nuclear isomers. [9] The primary decay mode before the most abundant stable isotope, 52 Cr, is electron capture and the primary mode after is beta decay. [9] 53 Cr is the radiogenic decay product of 53 Mn (half-life 3.74 million years). [24] Chromium isotopes are typically collocated (and compounded) with ...
The primary chromium ore is the mixed metal oxide chromite, FeCr 2 O 4, found as brittle metallic black crystals or granules. Chromite ore is heated with a mixture of calcium carbonate and sodium carbonate in the presence of air. The chromium is oxidized to the hexavalent form, while the iron forms iron(III) oxide, Fe 2 O 3:
California has set a limit for the toxic heavy metal hexavalent chromium in drinking water. Advocates have called for a stricter limit, warning of health risks.
Aside from its central role in the production of chromium from its ores, sodium chromate is used as a corrosion inhibitor in the petroleum industry. [3] It is also a dyeing auxiliary in the textile industry. [3] It is a diagnostic pharmaceutical in determining red blood cell volume. [4]
Chrome plating (less commonly chromium plating) is a technique of electroplating a thin layer of chromium onto a metal object. A chrome plated part is called chrome, or is said to have been chromed. The chromium layer can be decorative, provide corrosion resistance, facilitate cleaning, and increase surface hardness. Sometimes a less expensive ...
The chromate coating process starts with a redox reaction between the hexavalent chromium and the metal. [2] In the case of aluminum, for example, Cr 6+ + Al 0 → Cr 3+ + Al 3+ The resulting trivalent cations react with hydroxide ions in water to form the corresponding hydroxides, or a solid solution of both hydroxides: Cr 3+ + 3 OH − → Cr ...