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在紫外光区四氯化碳的吸收光谱和它在水中的吸收光谱并不相同.在波长2000-2500??的范围内,四氯化碳在纯水中的吸收光谱有一高峰出现于λ=2085??的位置.在这峰上,体系的光密度和四氯化碳在水中的浓度成正比,顺从Beer定律. 我们的有限经验发现在某些盐水溶液中[(CH_3)_4NCl,(CH_3)_4NBr,NaClO_3,NaBr,CsCl和HCl],四氯化碳的吸收峰发生移动.但是浓度不太大的锂、钠、钾、钙的氯化物和钠、钾、镁的硫酸盐的水溶液中,四氯化碳的吸收峰仍在λ=2085??,并且不随盐的浓度的变化而移动.在这波长上,Beer定律仍能适用. 我们用分光光度计在25℃下(除氯化锂溶液是在20°外)测定不同浓度的上述七种盐溶液中四氯化碳的活度系数f,得到七条直线形的logf对C_5(克分子/升)的图.这些盐对四氯化碳都起盐析作用,盐析次序是如果浓度单位是离子强度μ,从logf对μ的图得到的盐析次序是: Na_2SO_4>K_2SO_4>NaCl>KCl>CaCl_2>MgSO_4>LiCl此盐析次序不合离子大小的次序(离子愈小,盐析愈大);偏差特别显著的是含很小离子的盐,氯化锂和硫酸镁. 以μ为浓度单位,我们根据内压力的盐析理论,计算锂、钠、钾的氯化物和钠、镁的硫酸盐五种盐溶液对四氯化碳的盐析常数k_μ.这些k_μ的值约为实验k_μ值的两倍多至三倍多,但是前者的盐析次序却和后者的相符.这个事实指出Bernal-Fowler的小离子对周围水分子结构的影响的理论和内压力的盐析理论有定性的正确性.
The absorption spectrum of CTC in UV light is not the same as its absorption spectrum in water, and the absorption spectrum of CTC in pure water has a peak at λ = At this peak, the optical density of the system is proportional to the concentration of carbon tetrachloride in water, obeying the Beer’s law. Our limited experience has shown that in some brine solutions, [(CH_3) _4NCl, (CH_3 ) _4NBr, NaClO_3, NaBr, CsCl and HCl], the absorption peak of carbon tetrachloride shifts, but the concentrations of lithium, sodium, potassium, calcium chloride and sodium, potassium and magnesium sulfate in aqueous solution are not too high , The absorption peak of carbon tetrachloride is still at λ = 2085 °, and does not move with the change of salt concentration. At this wavelength, Beer’s law still applies. We use a spectrophotometer at 25 ° C Lithium solution was measured at 20 ° C) to determine the activity coefficient f of carbon tetrachloride in the above seven salt solutions at different concentrations to obtain seven linear logf vs. C_5 (mol / l) Carbonization plays a salting-out role, and the salting-out order is if the concentration unit is the ionic strength μ, and the salting-out order from logf to μ is: Na_2SO_4> K_ 2SO_4> NaCl> KCl> CaCl_2> MgSO_4> LiCl The order of the salting out does not fit the order of the ions (the smaller the ions, the larger salting out); the most notable deviations are salts with small ions, lithium chloride and magnesium sulphate. Based on the salting-out theory of internal pressure, we calculate the salting-out constants k_μ of carbon tetrachloride for five salt solutions of lithium, sodium and potassium chlorides and sodium and magnesium sulphates in μ concentration units. These k_μ values About twice to three times as much as the experimental k_μ value, but the former’s salting-out order is consistent with the latter.The fact that Bernal-Fowler’s theory of the effect of small ions on the surrounding water molecules and the salt of internal pressure Analysis of the theory is qualitative correctness.