Naphthalene solid

Figure 13.4 (a) Absorption spectra of benzophenone (ethanol, 20°C) and naphthalene (ethanol + methanol, — 180°C). (b) Phosphorescence emission spectra at — 190°C in ether + ethanol, under steady irradiation at 3660 A. Benzophenone, 2 x 10 2 M benzophenone + naphthalene, 2 x 10-2 M and 3.2 x 10-1 M, respectively concentration of pure naphthalene (solid line) not known. From A. Terenin and V. Ermolaev, Trans. Faraday Soc., 52, 1042 (1956). Reproduced by permission of the Faraday Society. 

A 100,000 lb/h (4536 kg/h) 70°C (158°F) feed containing 80 wt % naphthalene is fed to a cooling crystallizer. At what temperature should the crystallizer operate for maximum naphthalene-only solids production At this temperature, what is the solids yield of naphthalene What is the total energy removed from the crystallizer Naphthalene solids are removed from the mother liquor by centrifugation, leaving some of the solids liquor (10 wt % of the solids) adhering to the solids. After the solids are melted, what is the final purity of the naphthalene ... 

CCRIS 7916 EINECS 215-329-7 HSDB 1143 Methyl naphthalene Methyl naphthalene (molten) Methylated naphthalenes Methyinaftalen Methyinaphthalene 2-Methylnaphthalene Methylnaphthalenes, liquid Methyl-naphthalenes, solid Methyinapthalene Naphthalene, methyl-. Mixture of a- and p-isomers. Has been used as an insecticide. Mixture of isomers of methyinaphthalene. 

Benzene is another kind of hydrocarbons, called aromatic compounds. It takes a hexagon shape, whose chemical structure resembles a unit of beehive. It is liquid at room temperature. That is, it has a sufficiently strong interaction among the molecules to be liquid, but not strong enough to be solid. When two benzene molecules are combined, a compound called naphthalene results. It is a solid with a special odor at room temperature and used as mothball. Why is naphthalene solid, whereas benzene is liquid at room temperature Think about it in terms of London force. It must be noted that the interaction between benzene molecules or naphthalene molecules is not only due to London force but also due to another kind. 

Fig. 12 Band narrowing computed for the naphthalene solid with (Holstein-Peierls) and without (Holstein) the effect of nonlocal electron-phonon coupling using the canonical transformation methods.

Finally, it has been possible to obtain LEED patterns from films of molecular solids deposited on a metal-backing. Examples include ice and naphthalene [80] and various phthalocyanines [81]. (The metal backing helps to prevent surface charging.)... 

Water at 20°C rests on solid naphthalene with a contact angle of 90°, while a water-ethanol solution of surface tension 3S dyn/cm shows an angle of 30°. Calculate (a) the work of adhesion of water to naphthalene, (b) the criticd surface tension of naphthalene, and (c) y for naphthalene. 

Students should carry out the purification by steam distillation of (a) crude nitrobenzene or chlorobenzene, or of (b) crude naphthalene, o-nitrophenol (p. 170) or />-tolunitrile (p. 194) as examples of solid compounds which may also be purified in this way. When the distillation is complete, disconnect the tubing (Fig. 15) between C and D before removing the flame from under D, otherwise the contents of C will be sucked back into D as the latter cools. 

Naphthalene, CioHs, colourless solid, m.p. 80°, insoluble in water, soluble in alcohol, characteristic odour. Anthracene, CjH4 C2H2 CjH4, m.p. 216°, white crystals when pure, with a faint blue fluorescence, but often very pale yellow crystals insoluble in water, slightly soluble in alcohol. Phenanthrene, m.p. 98°, and biphenyl, m.p. 69°, are white solids. 

Effect of impurities upon the melting point. Let us take a specific example and examine the effect of the addition of a small quantity of naphthalene to an equilibrium mixture of pure solid and liquid a-naphthol at the temperature of the true melting point (95 5°) at atmospheric pressure. 

The naphthalene wUl dissolve in the liquid a-naphthol and, according to Raoult s law, the vapour pressure of the latter will be reduced. Hence a-naphthol will pass preferentially into the liquid phase and, if the external temperature is maintained at 95 5°, the ultimate result will be the complete melting of the solid a-naphthol since melting requires heat and no heat is imparted to the system, the temperature will fall. 

Picrates, Many aromatic hydrocarbons (and other classes of organic compounds) form molecular compounds with picric acid, for example, naphthalene picrate CioHg.CgH2(N02)30H. Some picrates, e.g., anthracene picrate, are so unstable as to be decomposed by many, particularly hydroxylic, solvents they therefore cannot be easily recrystaUised. Their preparation may be accomplished in such non-hydroxylic solvents as chloroform, benzene or ether. The picrates of hydrocarbons can be readily separated into their constituents by warming with dilute ammonia solution and filtering (if the hydrocarbon is a solid) through a moist filter paper. The filtrate contains the picric acid as the ammonium salt, and the hydrocarbon is left on the filter paper. 

The commercial product, m.p. 53-55°, may be used. Alternatively the methyl -naphthyl ketone may be prepared from naphthalene as described in Section IV,136. The Friedel - Crafts reaction in nitrobenzene solution yields about 90 per cent, of the p-ketone and 10 per cent, of the a-ketone in carbon disulphide solution at — 15°, the proportions ore 65 per cent, of the a- and 35 per cent, of the p-isomer. With chlorobenzene ns the reaction medium, a high proportion of the a-ketone is also formed. Separation of the liquid a-isomer from the solid p-isomer in Such mixtures (which remain liquid at the ordinary temp>erature) is readily effected through the picrates the picrate of the liquid a-aceto compound is less soluble and the higher melting. 

Purification of solid by recrystallisation acetanilide from water naphthalene from methylated spirit (III,5). Use 1 g. of solid, 25 ml. flask and short water condenser. 

Davies and Warren" found that when 1,4-dimethylnaphthalene was treated with nitric acid in acetic anhydride, and the mixture was quenched after 34 hr, a pale yellow solid with an ultraviolet spectrum similar to that of a-nitro-naphthalene was produced. However, if the mixture was allowed to stand for 5 days, the product was i-methyl-4 nitromethylnaphthalene, in agreement with earlier findings. Davies and Warren suggested that the intermediate was 1,4-dimethyl-5 nitronaphthalene, which underwent acid catalysed rearrangement to the final product. Robinson pointed out that this is improbable, and suggested an alternative structure (iv) for the intermediate, together with a scheme for its formation from an adduct (ill) (analogous to l above) and its subsequent decomposition to the observed product. 

Naphthalene is a white crys talline solid melting at 80 C that sublimes readily It has a characteristic odor and was formerly used as a moth repellent... 

Figure 22-8 shows the features of a horizontal center-fed column [Brodie, Au.st. Mech. Chem. Eng. Tran.s., 37 (May 1979)] which has been commercialized for continuous purification of naphthalene and p-dichlorobenzene. Liquid feed enters the column between the hot purifying section and the cold freezing or recovery zone. Ciystals are formed internally by indirect cooling of the melt through the walls of the refining and recovery zones. Residue liquid that has been depleted or product exits from the coldest section of the column. A spiral conveyor controls the transport of solids through the unit. 

Experimental gas-solid mass-transfer data have been obtained for naphthalene in CO9 to develop correlations for mass-transfer coefficients [Lim et al., Am. Chem. Soc. Symp. Ser, 406, 379 (1989)]. The data were correlated over a wide range of conditions with the following equation for combined natural and forced convection ... 

Liquid/Solid Mass Transfer The dissolved gas and the solvent react in contact with the surface of the catalyst. For studying the rate of transfer to the surface, an often-used system was benzoic acid or naphthalene in contact with water. A correlation of Dharwadkar and Sylvester (AJChE Journal, 23, 376 [1977]) that agrees well with some others is... 

Naphthalene-l-sulfonyl chloride [85-46-1] M 226.7, m 64-67°, 68°, b 147.S°/0.9mm, 147.S°/13mm. If the IR indicates the presence of OH then treat with an equal weight of PCI5 and heat at ca 100° for 3h, cool and pour into ice + H2O, stir well and filter off the solid. Wash the solid with cold H2O and dry the solid in a vacuum desiccator over P2O5 + solid KOH. Extract the solid with pet ether (b 40-60°) filter off any insoluble solid and cool. Collect the crystalline sulfonyl chloride and recryst from pet ether or C6H6 pet ether. If large quantities are available then it can be distd under high vacuum. [Fierz-Davaid and Weissenbach Helv Chim Acta 3 2312 1920.] The sulfonamide has m 150° (from EtOH or H2O). 

Fillers are often employed to reduce the surface tack of the final product. Examples are talc and china clay. If powdered materials are added directly to a latex they compete for the emulsion stabiliser present and tend to coagulate the latex. They are therefore added as an aqueous dispersion prepared by ball milling the filler with water and a dispersing agent, for example a naphthalene formaldehyde sulphonate at a concentration of about 1% of the water content. Heat and light stabilisers which are solids must be added in the same way. 

Fumaric acid may be prepared by heating maleic acid, with or without catalysts. It is also obtained as by-product in the manufacture of phthalic anhydride from naphthalene. The acid is a solid melting at 284°C. Fumaric acid is sometimes preferred to maleic anhydride as it is less corrosive, it tends to give lighter coloured products and the resins have slightly greater heat resistance. 

The prime function of the saturated acid is to space out the double bonds and thus reduce the density of cross-linking. Phthalic anhydride is most commonly used for this purpose because it provides an inflexible link and maintains the rigidity in the cured resin. It has been used in increasing proportions during the past decade since its low price enables cheaper resins to be made. The most detrimental effect of this is to reduce the heat resistance of the laminates but this is frequently unimportant. It is usually produced by catalytic oxidation of o-xylene but sometimes naphthalene and is a crystalline solid melting at 131°C. 

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