EQUILIBRIUM IN THE SYSTEM LITHIUM CHLORIDE: QUINO-LINE

James H. Walton, Clarence R. Wise
1922 Journal of the American Chemical Society  
In connection with a series of tests on quinoline as a solvent it was found that the solubility of lithium chloride in this substance decreases markedly with rise in temperature. This difference in solubility is sufficient to produce a fairly voluminous crystalline precipitate when a solution saturated a t room temperature is heated to the neighborhood of the boiling point. This paper deals with the solubility of lithium chloride in quinoline a t various temperatures. Experimental Reagents.-The
more » ... ental Reagents.-The lithium chloride was the purest obtainable on the market. It was purified by recrystallizing from absolute alcohol and drying a t 160', and was found free from sodium, potassium, and the nitrate and sulfate ions. Analysis of the chlorine content showed the substance to be 99.8% pure. The quinoline was dried by allowing it to stand over potassium hydroxide, then over barium oxide, from which it was then distilled. The product obtained in this way was amber colored. To obtain an absolutely colorless liquid a t least 6 redistillations were necessary. The colorless product obtained in this way distilled a t 231.4' a t 740.5 mm. The boiling point is given in the literature a t 237-239' a t 760 mm. On standing in the light, quinoline becomes discolored, but a sample preserved in a bottle coated with asphalt paint showed no change in color after 6 months. Apparatus.-The samples of the liquid phase were taken in an apparatus described by Walton and Judd' which permits the sample to be filtered and collected in a weighing bottle without removing it from the constant-temperature bath. Between 0' and ,z 70' the ordinary type of thermostat was used; above that temperature vapor baths " B were used, the temperature of the vapors 5 on being kept constant by heating them under a presswe that was kept constant by means of O6 an automatic regulator.* 0 4 Procedure.-The drylithiumchlorozi--~ ide and quinoline were placed in the u 5 w TfVHQbTURZ tube and stirred until equilibrium was reached, about 48 hours being necessary. Samples of the liquid phase were taken about every 5 hours and the chlorine content determined by the Volhard method. When this was found to be constant a samp'le was analyzed for chlorine gravimetrically in the usual way. That the presence of quinoline introduces no error in the determination is 1
doi:10.1021/ja01422a012 fatcat:i62w6qspdjabla6w3oljpo7gb4