Compounds and solubility

Both the m- and -phenylenediamines are used to manufacture sulfur dyes, either by refluxing in aqueous sodium polysulfide, or heating with elementary sulfur at 330°C to give the leuco form of the dye. These dyes are polymeric, high molecular weight compounds, and soluble in base. The color is developed by oxidation on the fabric. 2,4-Toluenediamine and sulfur give Sulfur Orange 1 (14). 

Lines 21 -40. Physical data. The usual crystalline shape, density (note two values reported.), sublimation notation, boiling point data, and so on. K at 25° is the ionization constant of the acid the pH of the saturated solution (2.8 at 25°C) is given. The solubility data (Soly) is very complete, including water solutions at various temperatures, a bit about the phase diagram of the compound, and solubility in other solvents. Note that numerical data is given where possible. 

Dissociation constants of ionizable components can be determined using various methods such as potentiometric titrations [85] CE, NMR, [86] and UV spectrophotometric methods [87]. Potentiometric methods have been used in aqueous and hydro-organic systems however, these methods usually require a large quantity of pure compound and solubility could be a problem. Potentiometric methods are not selective because if the ionizable impurities in an impure sample of the analyte have a pK similar to that of the analyte, this could interfere with determining the titration endpoint. If the titration endpoint is confounded, then these may lead to erroneous values for the target analyte pKa. 

New combinations of ions could be CaCl2 and NaN03. But solubility guideline 4 tells us that CaCl2 is a soluble compound, and solubility guidelines 2 and 3 tell us that NaN03 is a soluble compound. Therefore no precipitate forms in this solution. 

Bromine (Br, at. mass 79.91) is a dark red-brown liquid. Saturated bromine water contains 3.6% (w/v) of bromine (at 20°C). Bromine forms bromide (Br) and hypobromite (BrO ) in alkaline solution. The most stable forms of bromine are bromide and bromate (BrOa ). Bromide has reducing properties, whereas bromine (Br2), hypobromite, and bromate are oxidants. Many bromides are sparingly soluble compounds, and soluble bromide complexes are formed with the same metals as form soluble chloride complexes. 

Iodine (I, at. mass 126.90) is a solid non-metal, which is fairly volatile at room temperature and sublimes easily. Iodine dissolves readily in aqueous KI solutions to yield the I,f complex, and is also soluble in organic solvents (CHCI3, CCI4, C6H6). It occurs mainly in the -I, V, and VII oxidation states. Iodide reveals reducing properties, whereas iodine, iodate, and periodate have oxidizing properties. Iodide, like chloride and bromide, forms sparingly soluble compounds and soluble complexes with some metals... 

Complexing Capacity of Known Organic Compounds and Soluble Organic Matter in Seawater by Differential Pulse Anodic Stripping Volt-ametry Peak Potential Shift, unpublished data. 

Equilibrium between insoluble compound and soluble phases, which is controlled by condition Eq. (2.20). 

We have many different classifications of compounds. We have ionic and covalent compounds, inorganic and organic compounds, and soluble and insoluble compounds. In this chapter, we will study acids and bases. See Figure 12.1. 

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