Reduction Definition and Examples in Chemistry

Reduction Definition and Examples in Chemistry Reduction involves a half-reaction in which a chemical species decreases its oxidation number, usually by gaining electrons. The other half of the reaction involves oxidation, in which electrons are lost. Together, reduction and oxidation form redox reactions (reduction-oxidation redox). Reduction may be considered the opposite process of oxidation. In some reactions, oxidation and reduction may be viewed in terms of oxygen transfer. Here, oxidation is the gain of oxygen, while reduction is the loss of oxygen. An old, less-common definition of oxidation and reduction examines the reaction in terms of protons or hydrogen. Here, oxidation is ​the loss of hydrogen, while reduction is the gain of hydrogen. The most accurate reduction definition involves electrons and oxidation number. Examples of Reduction The H ions, with an oxidation number of 1, are reduced to H2, with an oxidation number of 0, in the reaction: Zn(s) 2H(aq) → Zn2(aq) H2(g) Another simple example is the reaction between copper oxide and magnesium to yield copper and magnesium oxide: CuO Mg → Cu MgO Rusting of iron is a process that involves oxidation and reduction. Oxygen is reduced, while iron is oxidized. While its easy to identify which species are oxidized and reduced using the oxygen definition of oxidation and reduction, its harder to visualize electrons. One way to do this is to rewrite the reaction as an ionic equation. Copper(II) oxide and magnesium oxide are ionic compounds, while the metals are not: Cu2 Mg → Cu Mg2 The copper ion undergoes reduction by gaining electrons to form copper. The magnesium undergoes oxidation by losing electrons to form the 2 cation. Or, you can view it as magnesium reducing the copper(II) ions by donating electrons. Magnesium acts as a reducing agent. In the meantime, the copper(II) ions remove electrons from magnesium to form magnesium ions. The copper(II) ions are the oxidizing agent. Another example is the reaction that extracts iron from iron ore: Fe2O3 3CO → 2Fe 3 CO2 The iron oxide undergoes reduction (loses oxygen) to form iron while the carbon monoxide is oxidized (gains oxygen) to form carbon dioxide. In this context, iron(III) oxide is the oxidizing agent, which gives oxygen to another molecule. Carbon monoxide is the reducing agent, which removes oxygen from a chemical species. OIL RIG and LEO GER To Remember Oxidation and Reduction There are two acronyms that may help you keep oxidation and reduction straight. OIL RIG- This stands for Oxidation Is Loss and Reduction Is Gain. The species that is oxidized loses electrons, which are gained by the species that is reduced.LEO GER or Leo the lion says grr.- This stands for Loss of Electrons Oxidation while Gain of Electrons Reduction. Another way to remember which part of the reaction is oxidized and which is reduced is to simply recall reduction mean reduction in charge.

Two Kinds of Homage

Two Kinds of Homage Two Kinds of Homage Two Kinds of Homage By Maeve Maddox Way back in elementary school when we learned about feudalism, we were told that the medieval vassal paid homage to his lord. My teachers pronounced the word homage: [hom-ij]. Note: Some English speakers don’t pronounce the h in this homage. When I became interested in movie criticism, I came across the word homage in connection with the practice of incorporating a name or a scene or a bit of dialogue from an old movie within a new production. When I read the word in my head, I pronounced it [hom-ij]. The first time I heard the pronunciation [oh-mazh] in an interview with someone from the film industry, I thought I was hearing a new word. I soon realized that when movie people talk about homage, they give it a French pronunciation. That’s when I realized that homage is a kind of heteronym. heteronym: A word having the same spelling as another, but a different sound and meaning. Both versions have to do with showing respect for someone or something, but the latter is used in the context of art. In general use, homage now means â€Å"acknowledgement of superiority in respect of rank, worth, beauty, or some other quality.† It’s usually used in the expression â€Å"to pay homage to.† The other kind of homage is â€Å"a work of art or entertainment which incorporates elements of style or content characteristic of another work, artist, or genre, as a means of paying affectionate tribute.† It can also refer to an example of such a tribute within a work. I noticed one in an episode of the television police drama Castle. The episode was presented as a frame story. The â€Å"frame† was the present day investigation. The story within the frame followed the usual Castle characters in a plot set in the 1930s. The homage [oh-mazh] reenacted a scene from the James Cagney movie Public Enemy (1931). See if you can tell which kind of homage is meant in the following examples from the Oxford English Dictionary: He must do homage to Philip for his lands in Normandy and Anjou, accept Philip as his overlord. Before leaving the mountains Picasso embarked on a major homage to El Greco. There is no country in which so absolute a homage is paid to wealth. That vice pays homage to virtue is notorious; we call this hypocrisy. Her first volume, however, was not the battle cry of a new poetry; it was a homage to Keats. This character is named after Humphrey Bogarts Fred Dobbs in the 1948 film, The Treasure of the Sierra Madre, but its an homage that doesnt appear to make much sense. Proust pens homages to such modern inventions as the railroad, the telephone, the airplane. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:100 Beautiful and Ugly Words15 Words for Household Rooms, and Their SynonymsFew vs. Several