The Freezing-point, Boiling-point, and Conductivity MethodsChemical publishing Company, 1897 - 64 pàgines |
Altres edicions - Mostra-ho tot
The Freezing-point, Boiling-point, and Conductivity Methods Harry Clary Jones Visualització completa - 1897 |
The Freezing-point, Boiling-point, and Conductivity Methods Harry Clary Jones Visualització completa - 1897 |
The Freezing-point, Boiling-point, and Conductivity Methods Harry Clary Jones Visualització completa - 1897 |
Frases i termes més freqüents
acetic acid alcohol ammonia amount of substance Aniline Annalen applied asbestos base Beckmann Benzene boiling boiling-point method bulb calculated cell Chem chemical chloride coil concentration condenser conductivity method conductivity of solutions conductors contains a gram-molecular convenient cork cylinder different substances dilution directly dissociation dissolved substance ductivity electrodes electrolyte electrolytic dissociation Ether Ethyl alcohol form of apparatus freezing freezing-mixture freezing-point lowering freezing-point method give abnormally given solvent glass tube gram-molecular weight heat of fusion Hydrochloric acid ions laboratory large number liquid liter measure mercury Methyl Methyl iodide molecular conductivity molecular lowering molecular weight Naphthalene nitrate non-electrolytes number of molecules number of substances Ostwald permanganate phys placed platinum wire potassium Potassium chloride pure solvent Raoult resistance rheostat rise salt shown slightly dissociated sodium solu solvent produced specific conductivity stance stirrer sulphuric acid temperature thermometer tion Triphenylmethane vapor vapor-pressure vapor-tension vent Ztschr Ο.ΟΙΟ
Passatges populars
Pàgina 6 - T = temperature of solidification of the solvent, and A= the lowering of the freezing-point. Here as much of the solvent is allowed to solidify as would serve N for the solution of one molecule of the substance.
Pàgina 37 - This, for low-boiling solvents, is necessarily less accurate than the above-described method of procedure. After the solvent is weighed the glass stopper is removed, and the thermometer, fitted tightly into a cork, is placed in position, as shown in the drawing. The apparatus is then placed upon the stand in the mantle of asbestos, the cork removed from A, and the condenser attached. Heat is then applied and the solvent boiled. The size of the flame must be so regulated by means of a screw pinch-cock,...
Pàgina 34 - These are made by cutting foil into pieces about y± cm. square, bending the corners alternately up and down, to prevent them from lying too closely upon one another, and serrating the edges with scissors, to give a greater number of points from which the boiling can take place. The bulb of the thermometer is thus entirely surrounded by metal at very nearly its own temperature, except directly above.
Pàgina 37 - ... cm. The platinum plates are then introduced into the platinum cylinder, the end of the tube (A) closed with a cork, and the ground-glass stopper inserted in A. The apparatus is then set in a small beaker glass and weighed. The solvent is then introduced, and the whole reweighed. Great care must be taken that not enough solvent is employed to boil over from one side of the platinum cylinder to the other. In case a laboratory is not provided with a balance capable of weighing accurately 200 or...
Pàgina 37 - ... cork, is placed in position, as shown in the drawing. The apparatus is then placed upon the stand in the mantle of asbestos, the cork removed from A, and the condenser attached. Heat is then applied and the solvent boiled. The size of the flame must be so regulated by means of a screw pinch-cock, that the boiling is quite vigorous, but not so violent as to be of an irregular or explosive character. A quiet but very active boiling is absolutely essential to the success of the experiment. The time...
Pàgina 38 - ... is weighed, and a convenient number of these poured into the solvent, either through the condenser, or directly through the tube A when the solvent is not too volatile, and has ceased to boil. The tube is then reweighed, and the amount of substance introduced, thus ascertained. The boiling-point of the solution is then determined. The carrying out of a determination with a low-boiling solvent is a much easier process than with one boiling at a considerably higher temperature. Thus : when anisol...
Pàgina 9 - The application of the freezing-point method to the determination of molecular weights in solution...
Pàgina 34 - A,, which is 2 or 2-^ cm. in diameter, by means of a cork. When it is desired to protect the solvent from the moisture in the air, the top of the condenser tube should be provided with a tube containing calcium chloride or phosphorus pentoxide. During an experiment, the vessel A is closed above by a cork, through which the Beckmann boiling-point thermometer T passes.
Pàgina 1 - It has long been known that when a solid is dissolved in a liquid, the freezing-point of the solution is lower than that of the solvent. The...
Pàgina 36 - B, surrounded by an ordinary metallic cone, /, to protect the small flame from the effect of air currents. The glass vessel, A, is shoved down until it comes in contact with the wire gauze. Under these conditions a very small flame suffices when low-boiling solvents are employed, and not a large flame is required when a solvent like aniline is used. Carrying Out a Determination.