Metal/sulfur displacement

Nitrogen Displaces the Metal Phosphorus Displaces the Metal Oxygen Displaces the Metal Sulfur Displaces the Metal Fluorine Displaces the Metal Chlorine Displaces the Metal Bromine Displaces the Metal Iodine Displaces the Metal... 

Tiichloiomethanesulfenyl chloiide can be reduced to thiophosgene by metals in the presence of acid and by various other reducing agents. The sulfur-bonded chlorine of trichloromethanesulfenyl chloride is most easily displaced by nucleophilic reagents, but under some conditions, the carbon-bound chlorines are also reactive (54). 

Iron Precipitation. Rich sulfide ore or Hquated antimony sulfide (cmde antimony) is reduced to metal by iron precipitation. This process, consisting essentially of heating molten antimony sulfide ia cmcibles with slightly more than the theoretical amount of fine iron scrap, depends on the abihty of iron to displace antimony from molten antimony sulfide. Sodium sulfate and carbon are added to produce sodium sulfide, or salt is added to form a light fusible matte with iron sulfide and to faciHtate separation of the metal. Because the metal so formed contains considerable iron and some sulfur, a second fusion with some Hquated antimony sulfide and salt foHows for purification. 

It resembles tetracyanoethylene in that it adds reagents such as hydrogen (31), sulfurous acid (31), and tetrahydrofuran (32) to the ends of the conjugated system of carbon atoms suffers displacement of one or two cyano groups by nucleophilic reagents such as amines (33) or sodiomalononittile (34) forms TT-complexes with aromatic compounds (35) and takes an electron from iodide ion, copper, or tertiary amines to form an anion radical (35,36). The anion radical has been isolated as salts of the formula (TCNQ) where is a metal or ammonium cation, and n = 1, 1.5, or 2. Some of these salts have... 

C20-0109. In Zn purification by electrochemistry, ZnO is dissolved in sulfuric acid. Before deposition, zinc powder is added to displace less active metals, such as cadmium. Use E ° values and balanced equations to show how this is accomplished. 

An exception among organic molecules is the adsorption of thiourea since that gives no maximum on the AG° vs. plot. It was suggested " that such atypical behavior can be expected for any neutral molecule that has the normal to the surface component of the dipole moment sufficiently positive compared with the resulting dipole moment of n displaced water molecules. In the case of a TU molecule oriented with the sulfur atom toward the metal surface, the ratio of /iA// is approximately equal to 2.5 D. This value is greater than the dipole moment of water, thus fulfilling the condition of atypical behavior. The anomalous behavior of thiourea is probably due to the fact that only a few solute molecules satisfy this condition. 

Minerals such as euxenite, fergusonite, samarskite, polycrase and loparite are highly refractory and complex in nature. These minerals may be opened up by treatment with hydrofluoric acid. While metals such as niobium, tantalum and titanium form soluble fluorides, rare earth elements form an insoluble residue of their fluorides. Such insoluble fluorides are filtered out of solution and digested with hot concentrated sulfuric acid. The rare earth sulfates formed are dissolved in cold water and thus separated from the insoluble mineral impurities. Rare earth elements in the aqueous solution are then separated by displacement ion exchange techniques outlined above. 

Nickel has typical metallic properties it can be readily rolled, drawn into wire, forged, and polished. It is also ferromagnetic and a good conductor of both heat and electricity. Nickel is positioned after hydrogen in the electrochemical series and slowly displaces hydrogen ions from dilute hydrochloric and sulfuric acids. It reacts more rapidly with nitric acid. Nickel is highly resistant to attack by strong alkalis (Hawley 1981). Black nickel oxide readily yields nickel salts... 

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