Solid chlorine, electrical conductivity

The Electrical Conductivity of Solid Chlorine and Bromine Trifluorides... 

T he interest in conductivity measurements on fluorinated inorganic com pounds at cryogenic temperatures lies in the ability of these compounds to form ions for possible synthesis of potential solid oxidizers. In this study we are concerned with the conductivity measurements of solid chlorine and bromine trifluorides to determine their electrical conductivities and its bearing on structural problems. Specific conductivities of <10" at 0° C. (I) and 10 ohm-1cm. 1 (3) have been reported for chlorine trifluoride and 8.0 X l ohm-1cm. 1 at 25° C. (1) for bromine trifluoride. In this work a conductivity cell has been developed for measuring fluorine-containing oxidizers at cryogenic temperatures. The variations of conductivity with temperature of chlorine trifluoride have been measured from +11.3° C. (b.p.) to —130° C. (well below m.p., —83° C.) and of bromine trifluoride from -j-80° C. to —196° C. (m.p., 8.8° C.). Possible mechanisms are discussed. 

In this way neutral atoms of the two species will accumulate at the opposite electrodes and if they cannot combine with the material of the electrode, they will combine with one another in whatever way is characteristic of them. Molten sodium chloride, for example, can be electrolysed to yield sodium metal and chlorine gas. Since the drifting of the ions carries a drift of charge, a current flows and the amounts of metal and gas produced are proportional to the product of the current and the time during which it has flowed. Thus, in principle at least, the fact that a solid is ionically bonded can be ascertained by observing that it is an electrical insulator that melts to an electrically conducting liquid whose conduction is accompanied by electrolysis. 

Although there are 30 water quality parameters available, only 23 completely monitored parameters were selected. A total of 254 samples were used for the analysis. The 23 water quality parameters were dissolved oxygen (DO), biological oxygen demand (BOD), electrical conductivity (EC), chemical oxygen demand (COD), ammoniacal nitrogen (AN), pH, suspended solids (SS), temperature (T), salinity (Sal), turbidity (Tur), dissolved solid (DS), total solid (TS), nitrate (NO ), chlorine (Cl), phosphate (PO ), zinc (Zn), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), sodium (Na), E.coli and coUform. 

An example of a compound of this type is of course salt itself (i.e. common salt , sodium chloride). This forms colourless, brittle crystals, which melt to a colourless liquid at 801 C, and boil to a colourless vapour at 1413 C. In the solid, it has the electrical conductivity of an insulator, but the liquid has a conductivity of about 10 Q m . When a direct current is passed through the melt, chlorine gas is evolved at the positive electrode (the anode) and metallic sodium is formed at the negative electrode (the cathode). This process is used industrially for the preparation of sodium, except that the temperature is lowered by the addition of another salt, e.g. calcium chloride, which depresses the freezing point of the sodium chloride. 

In which of the following states would NaCl be electrically conducting (a) solid, (b) molten (that is, melted), (c) dissolved in water. Explain your answers. Beryllium forms a compound with chlorine that has the empirical formula BeC. How would you determine whether it is an ionic compound (The compound is not soluble in water.)... 

Polychlorinated biphenyls (PCBs) are colorless toxic organic substances that cause cancer and birth defects. There are more than 200 different types of PCBs, ranging in consistency from heavy, oily liquids to waxy solids, and each type further varying in the number and location of chlorine atoms attached to its molecular carbon rings. They are fire resistant and do not conduct heat or electricity well. Accordingly they have numerous commercial applications as insulation in electrical systems, for example, for transformers. 

Sodium chloride is plentiful as rock salt, but the solid does not conduct electricity, because the ions are locked into place. Sodium chloride must be molten for electrolysis to occur. The electrodes in the cell are made of inert materials like carbon, and the cell is designed to keep the sodium and chlorine produced by the electrolysis out of contact with each other and away from air. In a modification of the Downs process, the electrolyte is an aqueous solution of sodium chloride. The products of this chloralkali process are chlorine and aqueous sodium hydroxide. 

Pure elements at room temperature and atmospheric pressure can be solids, liquids, or gases. Some elements are colorless. Others, like the ones shown in Figure 1, are colored. Despite the differences between elements, groups of elements share certain properties. For example, the elements lithium, sodium, potassium, rubidium, and cesium can combine with chlorine in a 1 1 ratio to form LiCl, NaCl, KCl, RbCl, and CsCl. All of these compounds are white solids that dissolve in water to form solutions that conduct electricity. 

Similarly, the elements fluorine, chlorine, bromine, and iodine can combine with sodium in a 1 1 ratio to form NaF, NaCl, NaBr, and NaL These compounds are also white solids that can dissolve in water to form solutions that conduct electricity These examples show that even though each element is different, groups of them have much in common. 

ARSENIC HYDRIDE (7784-42-1) A thermallyunstable flammable gas. Violent reaction with acids, halogens, chlorine, oxidizers. This chemical is endothermic can be detonated by shock, elevated temperatures above (572°F/300°C), or powerful initiators. Exposure to light causes moist material to decompose with deposition of solid black arsenic. Low conductivity may cause the accumulation of static electrical charges, and cause ignition of its vapors. 

Ionic Bonding In Chapter 8 we saw that when solid sodium chloride is dissolved in water, the resulting solution conducts electricity, a fact that convinces chemists that sodium chloride is composed of Na" " and Cl ions. Thus, when sodium and chlorine react to form sodium chloride, electrons are transferred from the sodium atoms to the chlorine atoms to form Na and Cl ions, which then aggregate to form solid sodium chloride. The resulting solid sodium chloride is a very sturdy material it has a melting point of approximately 800 °C. See Figure 12.1. 

Year 12 Australian students asked about sodium chloride were found to often volunteer a description of how ions might be formed through an electron transfer event (i.e. from sodium atom to chlorine atom). It was also common for these students to refer to molecules of NaCl, and some believed that there were two types of bond in sodium chloride either that the NaCl molecules had internal covalent bonds, but were ionically bonded to other molecules, or vice versa (Butts Smith, 1987). Some of the students thought that this assumed molecular nature of sodium chloride explained why the solid did not conduct electricity, believing that ions were only formed from the molecules on dissolving. One student thought that each ion would have one ionic bond, and five physical bonds (p. 196). 

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