Metal-nonmetal reaction

Why can metal-nonmetal reactions always be assumed to be oxidation-reduction reactions ... 

When a metal reacts with a nonmetal, an ionic compound is formed. The ions are formed when the metal transfers one or more electrons to the nonmetal, the metal atom becoming a cation and the nonmetal atom becoming an anion. Therefore, a metal-nonmetal reaction can always be assumed to be an oxidation-reduction reaction, which involves electron transfer. 

Reacts with many metals to give hydrogen, sometimes violently. With non-metals pyrophoric hydrides may result. Frequently initiates explosive reactions between other substances. Violent reactions with many non-metal and some metal halides and oxyhalides, also with many organometallic compounds. Many metal nonmetal-lides produce toxic, flammable or pyrophoric gases on contact with diprotium monoxide. 

Remember that metals + nonmetals form ionic bonds, while the reaction of two non-metals forms a covalent bond. 

Chemical properties of iodine are quite similar to those of other halogens, especially chlorine and bromine. However, being less electronegative than chlorine and bromine, its reactivity towards most metals, nonmetals, and their compounds may differ vastly. All iodine reactions occur in vapor phase or aqueous media. Vapor phase reactions require elevated temperatures. 

Transition metal nitrides and carbides can be described, generally speaking, as insertion compounds of nitrogen or carbon in the metal network.1 In fact, strong metal-nonmetal interactions exist which induce structural modifications.1,2 These compounds form a class of materials with unique physical3,4 and catalytic1,5,6 properties. The term platinoids has been used to illustrate their potential in reactions traditionally catalysed by noble metals. 

Direct evidence for the formation of radical o-quinone (and sometimes p-qui-none) complexes was established in the studies quoted above. Various synthetic techniques starting from elemental metals, nonmetals, metal salts, and complexes have been developed for obtaining these coordination compounds. The peculiarities of their thin structure and physical-chemical properties were investigated. The obtained products have practical applications, in particular for medical purposes. Quinone-based metal complexes have a potential applicability as cocatalysts in a wide range of reactions involving electron exchange between substrate and catalysts. Further studies in this field and on mechanisms of electron mobility between the metal center and the o-quinone ligands are still necessary to understand the vast and complex redox chemistry of these compounds. 

Chlorate(Vll) salts most metal, nonmetal, amine, and organic cation chlorates(Vll) can be detonated or undergo violent reaction in contact with combustible materials Diazo compounds such as CH2N2 Diazonium salts, when dry Fulminates... 

The relatively few nonmetals appear in the upper right-hand corner of the table (to the right of the heavy line in Fig. 2.21), except hydrogen, a non-metal that is grouped with the metals. The nonmetals typically lack the physical properties that characterize the metals. Chemically, they tend to gain electrons to form anions in reactions with metals. Nonmetals often bond to each other by forming covalent bonds. For example, chlorine is a typical... 

Kanury, A. M., A kinetic model for metal -I nonmetal reactions. MetalL Trans. A, 23A, 2349 (1992). 

All nonmetals add to the alkaline earth metals with two noteworthy exceptions Mg does not react with elemental carbon, and Be fails to react with H2. A review of homonuclear, cluster-type compounds, also including group IIA metal-nonmetal compounds, is available. The reaction of Mg with H2 requires rather drastic conditions unless homogeneous catalysts are present (see also 10.2.3.3.1). 

The Dalton theory of the atom and related ideas were the basis for our study of composition stoichiometry (Chapter 2) and reaction stoichiometry (Chapter 3), but that level of atomic theory leaves many questions unanswered. Why do atoms combine to form compounds Why do they combine only in simple numerical ratios Why are particular numerical ratios of atoms observed in compounds WToy do different elements have different properties WToy are they gases, liquids, solids, metals, nonmetals, and so on Why do some groups of elements have similar properties and form compounds with similar formulas The answers to these and many other fascinating questions in chemistry are supplied by our modern understanding of the nature of atoms. But how can we study something as small as an atom ... 

Sources for hydrogen include 1) electrolysis of a suitable electrolyte solution in water, 2) reaction of steam with a metal, 3) reaction of water with a nonmetal, and 4) synthesis gas or water gas. From the Ellingham diagram, the water-gas shift reaction is feasible below about 1100 K,... 

For more practical purposes, therefore, one should take recourse to metal particles as produced by other means, in particular on supports or in matrices. The advantage is the availability of macroscopic amounts of sample the disadvantage is that interaction with the supporting medium must be assessed. A great variety of synthetic methods exists, of which we can mention only a few. Metal clusters can be produced by aerosol techniques, by vapor deposition, by condensation in rare-gas matrices, by chemical reactions in various supports, e.g. zeolites, SiOi, AI2O3, or polymer matrices. Many different metal-nonmetal composites, such as the ceramic metals (cermets) have been obtained with metal particles with sizes varying from nanometers upward. In alternative approaches, metal particles are stabilized by chemical coordination with ligand molecules, as in metal colloids and metal cluster compounds. 

OBJECTIVE To learn about metal-nonmetal oxidation-reduction reactions. 

Nonmetals lack metallic luster and are generally poor conductors of heat and electricity. Several are gases at room temperature. Compounds composed entirely of nonmetals are generally molecular. Nonmetals usually form anions in their reactions with metals. Nonmetal oxides are acidic they react with bases to form salts and water. Metalloids have properties that are intermediate between those of metals and nonmetals. 

Properties Yel. fuming liq. dec. in water (reactive) m.w. 221.90 dens. 3.189 m.p. 9.4 C b.p. 98 C Toxicology ACGIH TLV/TWA 2.5 mg(F)/m (air) poison toxic by ing., inh., and skin contact corrosive to skin and mucous membranes causes severe burns TSCA listed Precaution Oxidizer dangerous fire risk attacks glass reacts violently with water, potassium hydroxide explosive reaction with benzene (> 50 C), potassium, molten sodium incandescent reaction with calcium carbide, metals, nonmetals... 

Precaution Violent or explosive reaction with chlorinated rubber (> 200 C), fluoroelastomers ( 200 C) incompat. with Cl, metals, nonmetals reacts violently with hydrogen peroxide, strong oxidizing agents... 

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