Practical Work in Organic ChemistryE. & F.N. Spon, 1891 - 156 páginas |
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Termos e frases comuns
acetic acid action added alcohol aldehyde alkali allowed ammonia aniline apparatus asbestos beaker benzene boiling boiling-point bottle bromine bulb calcium chloride caoutchouc stopper carbon and hydrogen carbon dioxide caustic potash cinnamic cinnamic acid cold water collected colour combustion combustion-tube condenser connected containing cool copper oxide cork crucible crystallise crystals current of steam decomposed Determination dilute dissolved distillate dried drops ether ethyl evaporation filtrate fraction funnel gently glass tube glycerol grams heat hydrochloric acid ignited inches isatin layer liquid litre melting melting-point methylated spirit mixed mixture nitrate nitric acid nitrobenzene nitrogen obtained oleic acid operation oxalic acid oxamide oxygen pass phenol piece platinum potassium hydroxide powdered precipitate Preparation pure purified reaction residue retort salt sample saponification separated small quantity sodium carbonate solvent specific gravity stearic acid strong sulphuric acid substance sulphate sulphuric acid temperature test-tube thermometer tion vapour washed water-bath weight
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Página 38 - Freezing Point Depression The decrease in the freezing point of a solvent caused by the presence of a solute.
Página 137 - ... distilled water. The whole is then evaporated with slight agitation to 35 parts. The mixture becomes thick and turbid on adding the solution of alum, but on heating over a water bath and stirring carefully, the mixture soon becomes clear and transparent.
Página 135 - ... hours, till the indigo is reduced and the sediment has sunk to the bottom. A portion of the clear liquor is then drawn off with a siphon, and the quantity of liquid having been accurately measured, it is mixed with an excess of hydrochloric acid, and the precipitate, after having been oxidised (by exposure to the air), is collected on a weighed filter, and washed with water.
Página x - ... introduced into them. A small quantity of the substance to be tested is placed in one of the tubes, enough to make a minute column of about 5mm in height. The tube containing the substance is fastened to a thermometer by means of a small rubber band cut from a piece of rubber tubing. The band is placed near the upper part of the tube, and the lower part of the tube, containing the substance, is placed against the bulb of the thermometer. Now a beaker glass of about 100CC capacity is filled with...
Página 99 - ... at a red heat. The ammoniacal liquor and naphtha are collected together in a graduated cylinder, which is changed as soon as a drop of the distillate sinks when collected in a testtube of water. After standing, to allow perfect separation of the ammoniacal liquor and light oils, the volume of each is observed, and, if desired, the strength of the former can be ascertained in the usual way by distillation with lime and titration of the distillate. The quantity of light oils is too small for further...
Página 100 - The next fraction of the distillate is rich in anthracene, and not unfrequently condenses in the neck of the retort as a yellow, waxy substance, which may be melted out by the local application of a small Bunsen flame. "The collection of anthracene oil is complete when no more distillate can be obtained, and the pitch intumesces and gives off heavy yellow fumes. The distilled fraction is then measured and cooled thoroughly, and the resultant pasty mass pressed...
Página 99 - The quantity of light oils is too small to allow of any further fractionation for benzols, etc. " The next fraction of the distillate consists of creosote oil. At first it will contain much naphthalene, and will probably solidify in white crystals on cooling, but afterwards a more fluid distillate is obtained. At a still later stage, a drop of the distillate collected on a cold steel spatula will be found to deposit amorphous solid matter of a yellow or greenish-yellow color, when the receiver is...
Página 137 - Í8 over. If no effervescence takes place, in consequence of the indigo being mixed with too much water, and if the boiling is continued, whilst more and more nitric acid is added, a violent reaction suddenly ensues when the solution has reached a certain concentration, the mass overflowing the vessel even -when it is very capacious, and the residue contains generally nitrosalicylic acid.
Página 137 - ... blue colour has disappeared, for which, from 600 to 700 grms. of nitric acid are necessary. The solution is boiled with several quarts of water, and filtered at the boiling heat, as rapidly as possible ; after 12 hours, the isatin separates in reddish crystalline nodules. The mother-liquor is boiled with the undissolved residue and filtered, the operation being two or three times repeated : the last mother-liquor still yields isatin on evaporation. The crystals are moistened with water containing...
Página 137 - After each addition of nitric acid, it is necessary to wait until the effervescence is over. If no effervescence takes place, in consequence of the indigo being mixed with too much water, and if the boiling is continued, whilst more and more nitric acid is added, a violent reaction suddenly ensues when the solution has reached a certain concentration, the mass overflowing the vessel even when it is very capacious : the residue generally contains nitrosalieylic acid (Hofmann).— 2.