Silver compounds classification

DOT CLASSIFICATION Forbidden SAFETY PROFILE Severe explosion hazard. A more powerful detonator than copper acetylide. Explodes when heated to 120-140°C. Formed when silver-containing soludons contact acetylene. Upon decomposidon it emits acrid smoke and irritadng fumes. See also SILVER COMPOUNDS and ACETYLIDES. 

OSHA PEL TW A 0.01 mg(A /m3 ACGIH TLV WA 0.01 mg(Ag)/m3 DOT CLASSIFICATION Forbidden SAFETY PROFILE Explodes when heated above 270°C or on impact. Pure silver azide explodes at 340°. An electric field or irradiation by electron pulses can explode the crystals. Shock-sensitive when dry and has detonated 250°C. Solutions in aqueous ammonia explode above 100°C. Reacts to form more explosive products with iodine (forms iodine azide) bromine and other halogens. The presence of metal oxides or metal sulfides increases the azide s sensitivity to explosion. Mixtures with sulfur dioxide are explosive. When heated to decomposition it emits toxic fumes of NO,. See also AZIDES and SILVER COMPOUNDS. 

Although the elements, gold (Au), silver (Ag), tin (Sn), copper (Cu), lead (Pb), mercury (Hg), antimony (Sb), arsenic (As), carbon (C), iron (Fe), sulfur (S) and zinc (Zn) had been known since ancient times, the first scientific discovery of an element occurred in 1669, when Hennig Brand discovered phosphorus (P). During the next two hundred years various chemical and physical properties of elements and their compounds were studied by chemists. By 1869, a total of 63 elements had been discovered. As the number of known elements increased, scientists began to recognize patterns in properties and began to develop classification schemes. 

In contrast to the other elements of group 13, thallium is considered a soft acid in Pearson s soft/hard acid classification (see Hard Soft Acids and Bases).This makes the element and its derivatives unique, and leads to its potentially most outstanding feature the properties of thallium are a subtle blend of some of the most desirable properties of numerous other metals (e.g. heavy alkali metals, silver, mercury, and lead). Thallium compounds are stable in both oxidation states (-1-1 and -1-3). The trivalent cation is quite a strong oxidation reagent, since it is reduced to T1+ easily (standard redox potential E°(TP+ — Tl" ") = -1.25 V). The ease of this reduction is utilized in certain organic reactions. 

Classify each of the foUowing as an element, a compound, or a mixture. Justify your classification (a) coffee (b) silver (c) calcium carbonate (d) ink from a ballpoint pen ... 

In fact, the classification of chemical elements is valuable only in so far as it illustrates chemical behaviour, and it is conventional to use the term transition elements in a mote restricted sense. The elements in the irmer transition series from cerium (58) to lutetium (71) are called the lanthanoids those in the series from thorium (90) to lawrencium (103) are the actl-noids. These two series together make up the /block in the periodic table. It is also common to include scandium, yttrium, and lanthanum with the lanthanoids (because of chemical similarity) and to include actinium with the actinoids. Of the remaining transition elements, it is usual to speak of three main transition series from titanium to copper from zirconium to silver and from hafnium to gold. All these elements have similar chemical properties that result from the presence of unfilled d-orbltals in the element or (in the case of copper, silver, and gold) in the ions. The elements from 104 to 109 and the undiscovered elements 110 and 111 make up a fourth transition series. The elements zinc, cadmium, and mercury have filled d-orbltals both in the elements and in compounds, and are usually regarded as nontransition elements forming group 12 of the periodic table. 

A further useful classification of solid electrolytes is based upon whether the fast ion-conduction process is three-dimensional throughout the crystal lattice, as in the high temperature electrolytes and the silver salts, or is confined to two-dimensional layers, as in the beta alumina family of compounds, or to onedimensional tunnels, as in the hollandite materials such as... 

In general, a compound is termed soluble if it dissolves in water and insoluble if it does not. However, these classifications are a bit of an oversimplification. (In reality, solubility is a continuum and even insoluble compounds dissolve to some extent, though usually orders of magnitude less than soluble compounds.) For example, silver nitrate is soluble. If we mix solid AgN03 with water, it dissolves and forms a strong electrolyte solution. Silver chloride, on the other hand, is almost completely insoluble. If we mix solid AgCl with water, virtually all of it remains as a solid within the liquid water. 

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