Methanol water-NaBr

Table 9. Vapor-Liquid Equilibrium Data Correlation for Methanol-Water-NaBr system at 298.15°K... 

Another type of ternary electrolyte system consists of two solvents and one salt, such as methanol-water-NaBr. Vapor-liquid equilibrium of such mixed solvent electrolyte systems has never been studied with a thermodynamic model that takes into account the presence of salts explicitly. However, it should be recognized that the interaction parameters of solvent-salt binary systems are functions of the mixed solvent dielectric constant since the ion-molecular electrostatic interaction energies, gma and gmc, depend on the reciprocal of the dielectric constant of the solvent (Robinson and Stokes, (13)). Pure component parameters, such as gmm and gca, are not functions of dielectric constant. Results of data correlation on vapor-liquid equilibrium of methanol-water-NaBr and methanol-water-LiCl at 298.15°K are shown in Tables 9 and 10. 

Silica in 80-95% dioxane in the presence of HCI, KOH, and different 1 1 salts was studied in [314]. Silica in nonaqueous solvents containing 1 mass% of water in the presence of CsCl was studied in [3155]. Silica in methanol in the presence of KCl was studied in [282]. Quartz in DMSO in the presence of various 1-1 electrolytes was studied in [3156]. Quartz in ethanol in the presence of various 1-1 electrolytes was studied in [3157,3158]. Quartz in DMSO, acetone, and 1-butanol in the presence of NaBr or LiBr was studied in [3151]. Silica in methanol, acetonitrile, and methanol-water mixtures, with or without NaCl was studied in [1853]. Silica in 99.7% acetone in the presence of Nal and BU4NI was studied in [1908]. Titania in different 99% organic-1% water mixtures in the presence of CsCl and other 1-1 salts was studied in [3160]. Anatase in different organic solvents in the presence of CsOH and HCIO4 was studied in [3161].Titania in -alcohols in the presence of different salts was studied in [2037]. LIF, Cal 2, and MgF, in methanol, acetone, and nitroethane in the presence of NaF were studied in [3162]. Agl in ethanol at concentrations of LiNQ, up to 0.01 M was studied in [3163]. ("aSiO, in DMSO at different concentrations of NaBr and CaBr2 was studied in [3144]. Diamond in 96% ethanol in the presence of various 1-1 salts was studied in [3164]. 

Furter [91] has analyzed the state of the art from the point of view of employing the salt effect in industrial processes, especially in extractive distillation. In addition, he ha.s made up a list of references covering the years 1966 to 1977 [91 a]. Schubert et al. [92] investigated the effect of some metal chlorides and other salts on the isothermal = 60°C) phase equilibrium behaviour of the systems n-propanol-water, n-butanol-water and methanol-water. Using CH30H/H20/NaBr as an example, the method of predicting salt effects for vapour-liquid equilibria as developed by Schuberth has been extended to uusaturated solutions [92a]. 

The last table NaBr in Methanol-Water should have appeared in the section on Nonaqueous-Aqueous Mixtures starting on p. 287. 

TA-NaBr-MRNi was prepared by the reported method [3]. RNi (W-1 type) was prepared from 1.9 g of Raney nickel alloy (Kawaken Fine Chemical Co., Ni/Al = 42/58). To wash out the excess base and aluminum salts, a sufficient amount of deionized water was used with ultrasonic irradiation. The modifying solution was prepared by dissolving of (R,R)-tartaric acid (1 g) and NaBr (6 g to 10 g) in 100 ml of water and adjusting the pH to 3.2 with IN NaOH aqueous solution. RNi was heated in the modifying solution at 100 C for 1 hour, washed with water (50 ml), methanol (50 ml, twice), and THF (10 ml). The TA-NaBr-MRNi obtained by this method was immediately used for the hydrogenation. 

Pinho, S.P. and Macedo, E.A. Solublity of NaCl, NaBr, and KCl in water, methanol, ethanol, and their mixed solvents, J. Chem. Eng. Data, 50(l) 29-32, 2005. 

Included among the salts chosen for study were those that cause salting-out (NaBr, NaF, KCl, Li Cl) and salting-in (HgC ) of methanol in aqueous solutions. To test the technique described above, the vapor-liquid equilibria of systems of constant ratios of salt to solvent 2 were measured. For example, in cases where methanol is salted out, the experiments were done at constant salt-to-water ratios, and when methanol is salted in (salting-out of water), constant salt-to-methanol ratios were used. This was done by preparing a solution of a fixed salt molality and using it as component 2 in the equilibrium still. Thus, references to molality refer to the ratio moles of salt to 1000 g of solvent 2. 

Figure 5. Activity coefficients for methanol and water in NaBr system...

In Equation (8.1) SSP is the sum for each i component of the products of the weight fraction of solvent component (w) per the solubility of H2 in the pure component at standard conditions (S). The SSP is thus related to the concentration of dissolved H2 in solution. SSP is 1.6 for pure methanol and 0.14 for pure water. The productivity to H202 was found to depend linearly on this parameter. Increasing the alcohol s carbon chain increases the H2 solubility. For pure isopropanol the SSP is 2.7. The effect of promoters such as NaBr on H2 solubility is unclear, but at equivalent SSP the catalyst productivity is nearly half, as indicated above. 

An argon-degassed solution of 1.24g (0.01 mol) 75 and 8.4g (0.1 mol) 2,3-dimethylbut-2-ene in benzene (100 mL) is irradiated with a 250-W Hg-lamp in a double-walled immersion well using a filter solution (7g Pb(NO3)2-l-750g NaBr/lOOmL water, cut-off at X = 340 nm) as coolant for 12 h. After evaporation of the solvent and excess alkene the residue (2.0 g) consisting of a 3 1 mixture of trans- and m-fused bicyclo-octanones 76 and 77 is refluxed for 2h in a solution of 4g KOH in methanol (100 mL). After cooling to r.t. the mixture is neutralized with 5% aq. HC1, the methanol evaporated and the residue extracted three times with ether (25 mL). The... 

Modification 1) RNi was modified with a 100-ml solution containing 1 g of (R,R)-tartaric acid ((R,R)-TA) and 6 g of NaBr (pH of this solution had been adjusted to 3.2 with 1 mol/dm NaOH) for 1 h at 100 C. After removal of the modification solution, the catalyst was successively washed with deionized water, methanol, and THF. 2) FNiP was modified with a 100-ml solution of 1 g of (R,R)-TA and the given amount of inorganic salt (pH of this solution had been adjusted with 1 mol/dm NaOH) for 1 h at the temperature described in the text. The modification over 100°C was caried out in an autoclave. The catalyst was washed in the same manner as RNi. 3) HNi was modified with a 300-ml solution of 3 g of (R,R)-TA and 0.3 gofNaBr (pH of this solution had been adjusted to 3.5 with 1 mol/dm NaOH) for 1 h at 100°C. The catalyst was washed in the same manner as RNi. 

Isopropyl-3-methyl-4-thiocyanatophenol 13 Thymol (15 g) and NaSCN 2H20 (35 g) are dissolved in methanol (150 ml) saturated with NaBr. Bromine (20 g) in methanol (30 ml) saturated with NaBr is added to this solution at room temperature with stirring. After 30 min a six- to eight-fold amount of water is added, whereupon the product separates as an oil. This crystallizes in 2 h at 0°, is dried on porous plate, and after recrystallization with charcoal from light petroleum has m.p. 105° (yield 95 %). 

Bis(acyloxy)iodo]arenes in the presence of bromide anion in water also oxidize primary and secondary alcohols similarly to the (PhIO) /KBr system [11,12]. The oxidation of primary alcohols using ArI(OAc)2/KBr in water or aqueous methanol affords carboxylic acids or esters [9, 13], while the oxidation of secondary alcohols under similar conditions results in the formation of the respective ketones in excellent yields [14]. Aldehydes can be converted into methyl esters by a similar procedure using PhI(OAc)2/NaBr in an acidic aqueous methanol solution [15]. Likewise, acetals 3 can be converted into the corresponding hydroxyalkyl carboxylic esters 4 by oxidation with PhI(OAc)2/LiBr in water (Scheme 6.3) [16]. 

Intergranular corrosion of titanium (and various of its alloys) occurs in fuming nitric acid at room temperature (3- to 16-h tests). Addition of 1% NaBr acts as an inhibitor [30]. Similar corrosion of commercially pure titanium occurs in methanol solutions containing Br2, CB, or I2 or Br , CT, or 1 [31]. Water acts as an inhibitor. 

KBr in a mixture of dioxane (40 % by weight) and water A NaBr in methanol... 

A warmed agitated suspension of 1,5-diazacyclooctane dihydrobromide and NaOH in methanol treated with several drops of water until the neutralization reaction is complete, a small amount of water added to dissolve completely residual NaBr, filtered into a warm soln. of 3-indolecarboxaldehyde in methanol, and warmed 15 min. at 40-45° 9- (3-indolyl) -1,5-diazabicyclo [3.3.1] nonane. 

The solubility of 16 was studied in detail. Its Mgh solubility in water and methanol is useless for the envisaged amide coupling. On the other hand, solvents like DMF, dimethylacetamide or THE are not suitable solvents for 16. The only solvent we found was hot DMSO. However, after solution of the Gd con lex in Dh SO at 100°C it crystallizes out on cooling to room tenqterature. Only the addition of alkali netal salts to the solution in DMSO stabilizes the solution and prevents crystallization. In our hands the use of LiCl, LiBr or NaBr gave the best results (S3, 34). The N-hydroxysuccinimide (NHS) ester of 16 is easily obtained under standard conditions (dicyclohexylcarbodiimide) in DMSO with LiCl as additive. 

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