IonAn ion (ˈaɪ.ɒn,_-ən) is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons.
Hexavalent chromiumHexavalent chromium (chromium(VI), Cr(VI), chromium 6) is chromium in any chemical compound that contains the element in the +6 oxidation state (thus hexavalent). Virtually all chromium ore is processed via hexavalent chromium, specifically the salt sodium dichromate. Hexavalent chromium is key to all materials made from chromium. Approximately of hexavalent chromium were produced in 1985. Additional hexavalent chromium compounds include chromium trioxide and various salts of chromate and dichromate, among others.
Chromic acidChromic acid is an inorganic acid composed of the elements chromium, oxygen, and hydrogen. It is a dark, purplish red, odorless, sand-like solid powder. When dissolved in water, it is a strong acid. There are 2 types of chromic acid, they are: molecular chromic acid with the formula H2CrO4 and dichromic acid with the formula H2Cr2O7. The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide.
Chrome platingChrome 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, or increase surface hardness. Sometimes, a less expensive substitute for chrome such as nickel may be used for aesthetic purposes. Chromium compounds used in electroplating are toxic. In most countries, their disposal is tightly regulated.
Reduction potentialRedox potential (also known as oxidation / reduction potential, ORP, pe, , or ) is a measure of the tendency of a chemical species to acquire electrons from or lose electrons to an electrode and thereby be reduced or oxidised respectively. Redox potential is expressed in volts (V). Each species has its own intrinsic redox potential; for example, the more positive the reduction potential (reduction potential is more often used due to general formalism in electrochemistry), the greater the species' affinity for electrons and tendency to be reduced.
PermanganateA permanganate (p@r'maeNg@neit,_p3r-) is a chemical compound with the manganate(VII) ion, MnO4−, the conjugate base of permanganic acid. Because the manganese atom has a +7 oxidation state, the permanganate(VII) ion is a strong oxidising agent. The ion is a transition metal ion with a tetrahedral structure. Permanganate solutions are purple in colour and are stable in neutral or slightly alkaline media. The exact chemical reaction depends on the carbon-containing reactants present and the oxidant used.
Oxidizing agentAn oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or "accepts"/"receives" an electron from a (called the , , or ). In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized".
ChromiumChromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use.
Passivation (chemistry)In physical chemistry and engineering, passivation is coating a material so that it becomes "passive", that is, less readily affected or corroded by the environment. Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation in the air. As a technique, passivation is the use of a light coat of a protective material, such as metal oxide, to create a shield against corrosion.
Alkaline earth metalThe alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. Together with helium, these elements have in common an outer s orbital which is full— that is, this orbital contains its full complement of two electrons, which the alkaline earth metals readily lose to form cations with charge +2, and an oxidation state of +2.
