Periodic relationships of oxidation numbers

All elements when uncombined have oxidation numbers equal to 0. (Some atoms also have oxidation numbers equal to 0 in some of their compounds, by the way.) 

The minimum oxidation number of hydrogen is -1. That of any other nonmetallic atom is equal to its group number minus 8. That of any metallic atom is 0. 

Give three possible oxidation numbers for chlorine. 

Cl is in periodic group VIIA, and so its maximum oxidation number is +7 and its minimum oxidation number is 7 — 8 = — 1. It also has an oxidation number of 0 when it is a free element. 

EXAMPLE 14.6. Give the possible oxidation numbers for potassium. 

---

Determine the oxidation number of sulfur in each of the following substances (a) barium sulfate, BaS04, (b) sulfurous acid, H2SO3, (c) strontium sulfide, SrS, (d) hydrogen sulfide, H2S. (e) Based on these compounds what is the range of oxidation numbers seen for sulfur Is there any relationship between the range of accessible oxidation states and sulfur s position on the periodic table ... 

This result is in agreement with those reported by M. Iring, et al (2 ) for polypropylene and polyethylene. The oxygen consumption data indicate the oxidation of polyethylene consists of a complex group of reactions beyond the induction period with no single, simple relationship between the number of oxygen molecules consumed and the number of chain scissions. 

In the past 15 years, a number of reviews have appeared. Two general reviews appeared in the mid 70s Both of these reviews attempted to comprehensively survey the topic of porphyrin stereochemistry up to the time of publication. These two reviews are appropriately consulted for complete information of all work completed to that time. In addition, there have been a number of more specialized reviews pertaining to tetrapyrrole macrocyclic structure. An excellent article by Glusker has detailed the structural work on vitamin B12 derivatives. An early classic review examined the stereochemistry of hemes (iron porphyrinates) and their relationship to the function of the hemoproteins A review of trends in metalloporphyrin stereochemistry as a function of electronic state and position in the periodic table was written by the author in 1977 There are also two subsequent reviews in which the senior author has participated a 1983 article (with Martin Gouterman) that attempted to reach an understanding of control of spin state in metalloporphyrins and a 1981 article (with Christopher A. Reed) that catalogues spin-state/stereochemical relationships of the iron porphyrinates and the implications of these structures for the hemoproteins. Articles by Hoffinan and Ibers have discussed the use of oxidized porphyrins and phthalocyanine derivatives as molecular metals. It is not the intention of the present review to attempt to supplant any of these earlier reviews but rather to extend them when appropriate, new information is available. Further, we will review some additional topics that have not been considered previously. 

Relate Examine the tables of ions and their oxidation numbers, Figures i. 1 and i. 3, in the chapter Chemical Formulas and Chemical Compounds. Compare the elements that have multiple ions or oxidation states with the placement of those elements on the periodic table. What relationship is there between the ability to form multiple ions and where those elements are generally found on the periodic table ... 

The chemist is much concerned with the relationship between the structure and reactivity of substances. A knowledge of such a relationship enables the chemist to make new compounds which have certain desired properties. The Brdnsted acid-base reaction is a common and relatively simple reaction we therefore use it to discuss the relationship of structure and reactivity. We here restrict our discussion to the oxyacids and oxyanions. We will first present the facts about reactivity, and then we will present a broad concept to rationalize the relative reactivities. The acidity of oxyacids follows periodic patterns and is also influenced by the oxidation number of the central atom. 

Strengths of oxoacids can be affected by many variables. For example, you may wonder how acidity depends on oxidation number, or how it varies across a row of the Periodic Table. There is also the question of the relationship between the first, second, etc., dissociation constants of polybasic acids. 

As regards the l,l-bis(acylamido)-l-deoxyalditols, the first structural study was that of Fletcher and coworkers,69 who conducted oxidations with lead tetraacetate. These authors postulated an empirical relationship between the position of the oxidation curve in a graph and the number of hydroxyl groups present. They compared the curves afforded by a series of l,l-bis(acetamido)-l-deoxyalditols with those of alditols having the same number of free hydroxyl groups, and observed a close correspondence. At present, periodate oxidation is widely applied to these mono- or di-saccharide derivatives. Under controlled conditions, the methylation technique can also be applied.42... 

Metal-cluster skeletons are defined by the number of metal cluster electrons (MCE) this in turn is determined by the positions of the metallic elements in the periodic table, and by their oxidation states. A general principle is the availability of vacant metal coordination sites for the formation of metal-metal bonds and of the valence eleetrons to be used in the formation of these bonds. Metals in relatively low oxidation states are, therefore, favored and the value of MCE corresponds to the number of M M bonds if electron-precise 2c 2e bonding is assumed. Several empirical rules have been established which describe the relationships between MCE and cluster shape. " There is some variation in the modes by which the clusters are linked, depending on the oxidation states of the component metals and on the number of vacant coordination sites on metals. 

---