Oxygen binary compounds

Additional data on chromium-oxygen binary compounds are found in the literature (50,56,59,62,63). 

In 1817 Dobereiner found that if certain elements were combined with oxygen in binary compounds, a numerical relationship could be discerned among the equivalent weights of these compounds. Thus when oxides of calcium, strontium, and barium were considered, the equivalent weight of strontium oxide was approximately the mean of those of calcium oxide and barium oxide. The three elements in question, strontium, calcium, and barium were said to form a triad. 

C.19 Aluminum oxide, alumina, exists in a variety of crystal structures, some of which are beautiful and rare. Write the formula for aluminum oxide, which is a binary compound of aluminum and oxygen. The mass of a rectangular slab of aluminum oxide of dimensions 2.5 cm X 3.0 cm X 4.0 cm is 102 g. What is the density of aluminum oxide ... 

The chalcogenides are binary compounds of a chalcogen (i.e., the elements of Group Ilb zinc, cadmium, mercury) with a less electropositive element, such as those of Group VIb (oxygen, sulfur, selenium, and tellurium). This section covers the sulfides, selenides, andtellurides. Oxides are reviewed above in Ch. 11. Most of the chalcogenides have useful optical characteristics and their applications are usually found in optics. 

The first compounds to be discussed will be compounds of two nonmetals. These binary compounds are named with the element to the left or below in the periodic table named first. The other element is then named, with its ending changed to -ide and a prefix added to denote the number of atoms of that element present. If one of the elements is to the left and the other below, the one to the left is named first unless that element is oxygen or fluorine, in which case it is named last. The same order of elements is used in writing formulas for these compounds. (The element with the lower electronegativity is usually named first refer to Table 5-1.) The prefixes are presented in Table 6-2. The first six prefixes are the most important to memorize. 

Figure 7.5 Variation of equilibrium oxygen partial pressure (a) equilibrium between a metal, Ag, and its oxide, Ag20, generates a fixed partial pressure of oxygen irrespective of the amount of each compound present at a constant temperature (b) the partial pressure increases with temperature (c) a series of oxides will give a succession of constant partial pressures at a fixed temperature and (d) the Mn-O system. [Data from T. B. Reed, Free Energy of Formation of Binary Compounds An Atlas of Charts for High-Temperature Chemical Calculations, M.I.T. Press, Cambridge, MA, 1971.]...

Iron reacts with nonmetals forming their binary compounds. It combines readily with halogens. Reaction is vigorous with chlorine at moderate temperature. With oxygen, it readily forms iron oxides at moderate temperatures. In a finely divided state, the metal is pyrophoric. Iron combines partially with nitrogen only at elevated temperatures. It reacts with carbon, sulfur, phosphorus, arsenic, and silicon at elevated temperatures in the absence of air, forming their binary compounds. 

The chemical properties of selenium fall between sulfur and tellurium. Thus, selenium reacts with oxygen similarly to sulfur, forming two oxides, selenium dioxide, Se02 and trioxide, SeOs. The metal combines with halogens forming their halides. With nonmetals, selenium forms binary compounds exhibiting oxidation states +4 and -i-6. 

If a binary compound contains oxygen, and fonns an acid when made to unite with water, or a sdt when added to a base, it is termed an onhyMde or anihyim add. Thus,... 

In general, that element of the binary compound having the greater affinity for oxygen will take the hydroxyl group from water the element having the less oxygen... 

Let us now turn to cross effects proper between electronic and ionic fluxes. Considering the general nature of cross effects in crystals, our analysis will be performed in some depth. It gives us the tools for a correct application of SE transport theory (see Section 4.2.2) and explains to some extent the physical meaning of the cross coefficients. Let us illustrate the problem using a semiconducting binary compound such as a transition-metal oxide. In A, 0 crystals with the B1 structure, oxygen... 

As a metal, Np has a relatively low melting point ( -640°C), is very dense (20.45 g/cnr), and is ductile. The alpha form reacts with hydrogen, carbon, oxygen, sulfur, the halogens, and phosphorus to yield a number of binary compounds. 

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