Iodides elemental halogens

Oxo-l-propen-l-yl tellurimn iodides did not react with iodine. The attempt to prepare mixed (chloride, bromide) tellurium trihalides was unsuccessful a mixture of trichlorides and tribromides was formed. When 1,3-diphenyl-3-oxo-l -propen-1 -yl tellurium iodide was reacted with bromine, the bromide and elemental iodine were the only observed products. The 3-0X0-1-propen-1-yl tellurium trihalides are thermally unstable they decompose on mild heating to the tellurium halide and elemental halogen ... 

If an electric current is passed through aqueous solutions of sodium chloride, sodium bromide, and sodium iodide, the elemental halogens are produced at one electrode in each case, with hydrogen gas being evolved at the other electrode. If the liquid is then evaporated from the mixture, a residue of sodium hydroxide remains. Write balanced chemical equations for these electrolysis reactions. 

Phosphorus chlorides, bromides, and iodides can be made by direct oxidation of elemental phosphorus with the elemental halogen. PCI3, for example, which is a liquid at room temperature, is made by passing a stream of dry chlorine gas over white or red phosphorus ... 

Iodine is a bluish-black, lustrous solid, volatizing at ordinary temperatures into a blue-violet gas with an irritating odor it forms compounds with many elements, but is less active than the other halogens, which displace it from iodides. Iodine exhibits some metallic-like properties. It dissolves readily in chloroform, carbon tetrachloride, or carbon disulfide to form beautiful purple solutions. It is only slightly soluble in water. 

The equihbrium constant of this reaction is 5.4 x 10 at 25°C, ie, iodine hydrolyzes to a much smaller extent than do the other halogens (49). The species concentrations are highly pH dependent at pH = 5, about 99% is present as elemental at pH = 7, the and HIO species are present in almost equal concentrations and at pH = 8, only 12% is present as and 88% as HIO. The dissociation constant for HIO is ca 2.3 x 10 and the pH has tittle effect on the lO ion formation. At higher pH values, the HIO converts to iodate ion. This latter species has been shown to possess no disinfection activity. An aqueous solution containing iodate, iodide, and a free iodine or triodide ion has a pH of about 7. A thorough discussion of the kinetics of iodine hydrolysis is available (49). 

Monatomic anions, such as the Cl- ions in sodium chloride and the O2- ions in quicklime (CaO), are named by adding the suffix -ide and the word ion to the first part of the name of the element (the stem" of its name), as shown in Table D.l thus, S2 is a sulfide ion and O2 is an oxide ion. There is usually no need to specify the charge, because most elements that form monatomic anions form only one kind of ion. The ions formed by the halogens are collectively called halide ions and include fluoride (F ), chloride (Cl-), bromide (Br-), and iodide (I ) ions. 

Halogens, the elements in Group 17 of the periodic table, have the largest electron affinities of all the elements, so halogen atoms (a n readily accept electrons to produce halide anions (a a. This allows halogens to react with many metals to form binary compounds, called halides, which contain metal cations and halide anions. Examples include NaCl (chloride anion), Cap2 (fluoride anion), AgBr (bromide anion), and KI (iodide anion). 

Among the most useful compounds of the halogens are the hydrogen halides. Hydrogen iodide is not very stable, and it cannot be efficiently prepared by direct combination of the elements. Rather, as is... 

Displacement reactions involve one element displacing another element from solution The element that dissolves in the solution is more active than the element supplanted from solution. Within the halogen group the activity decreases from top to bottom. Thus, each halogen is able to displace the members of the group below it, but not those above it. For instance, molecular bromine can oxidize aqueous iodide ion but molecular iodine is incapable of oxidizing bromide ion ... 

There is only one simple anion commonly found in soil, and that is chloride (Cl ). Chloride is an essential nutrient for plants but is typically present in sufficiently high concentrations that deficiencies are never observed. If other halogens are present, they will also be present as simple anions. Most soils do contain small amounts of bromide as the second most common simple anion. In some cases, significant levels of fluoride and iodide may be present, although this is rare. These anions are generally soluble in water and tend to exist as the simple anion. However, they can combine with other components and exist as other species. For instance, halogens are present in organic compounds such as solvents, insecticides, and herbicides, which can be soil contaminants. There are also other nonionic species of these elements that may be present [20],... 

A variety of miscellaneous elements can also occur in a residual fuel oil fraction. For example, chlorine is present as a chlorinated hydrocarbon and can be determined (ASTM D808, D1317, D6160). A rapid test method suitable for analysis of samples by nontechnical personnel is also available (ASTM D5384) and uses a commercial test kit where the oil sample is reacted with metallic sodium to convert organic halogens to halide, which is titrated with mercuric nitrate using diphenyl carbazone indicator. Iodides and bromides are reported as chloride. 

Only a few compounds of americium exist. The most important is americium oxide (AmOj), whose main use is in the preparation of other compounds. Americium can also form compounds with the halogens, similar to other transuranic elements—for example, americium iodide (Aml ), americium fluoride, and americium chloride (AmF and ArnGl ). 

Hydrobromic acid reduces sulphuric add to sulphur dioxide, as also does hydriodic acid, but with the latter in high concentration the reduction goes further, producing sulphur and hydrogen sulphide.2 For this reason when metallic bromides and iodides are treated with sulphuric acid, the halogen element is liberated, the temperature at which this becomes evident depending on the concentration of the acid thus, with the potassium salts, the following observations have been made 3... 

All the halogen elements combine with tellurium. The powdered crystalline form is inflamed by fluorine in the cold 1 and by warm chlorine, the product in the latter case being the tetrachloride.2 With bromine the product is the dibromide, whilst iodine reacts only at a higher temperature, giving a tetra-iodide. Hydrogen chloride does not affect the element. 

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