Globule Testing

Caseade tests are useful in determining all aspeets of seeondary flow. For better visualization, tests have been eondueted in water easeades. The flow patterns are studied by injeeting globules of dibutyl phatalate and kerosene in a mixture equal to the density of water. The mixture is useful in traeing seeondary flow, sinee it does not eoagulate. 

The process involves removal of materials less dense than water (such as oil) and suspended materials that are more dense than water by settling. The API separator does not separate substances in solution, nor does it break emulsions. The effectiveness of a separator depends on the temperature of the water, the density and size of the oil globules, and the amounts and characteristics of the suspended materials. The susceptibility to separation (STS) test is normally used as a guide to determine what portion of the influent to a separator is amenable to gravity separation [38]. In terms of globule size, an API separator is effective down to globule diameters of 0.015 cm (15 microns). 

Likewise add a few drops of chlorine water and of bromine water to separate portions of an iodide solution, for example KI, and test in each case with carbon disulphide. Note that in each case the globule becomes violet colored. 

Procedure Treat 25 grams of mercury in a flask in the hood with 20 cc. of QN HNOs, warming gently, until no further action takes place. Allow to cool until the flask can be held in the hand, then pour the solution away from any remaining globule of mercury into a small dish, and leave to crystallize until the next day. Spread the crystals out on a filter paper placed on a paper towel and let them dry at room temperature. Put the product in a cork-stoppered test tube as soon as it is dry. 

Bromic and Iodic Acids. To a globule of carbon disulphide in a test tube add a few drops of bromine water until, after shaking, the globule has assumed a distinct red color. Add 5 cc. water and then chlorine water, a few drops at a time, shaking after each addition. The red color bleaches and finally disappears altogether. 

Fiberglass will often melt in the flame of an alcohol lamp and form round globules. Tweezers are useful for this test. If a combustion test is to be carried out, make sure that it is conducted in a safe area. 

Detection.—Many of the reactions described under the properties of ozone can be used for the detection of this gas in the air. Exposure to an ozone-laden atmosphere causes the formation of a film of oxide on the surface of a globule of clean mercury and so causes this to drag or tail when it moves.6 The formation of a stain of silver peroxide on a clean silver surface 7 supplies a very trustworthy test for ozone, but... 

Dry test. All compounds of mercury when heated with a large excess (7-8 times the bulk) of anhydrous sodium carbonate in a small dry test-tube yield a grey mirror, consisting of fine drops of mercury, in the upper part of the tube. The globules coalesce when they are rubbed with a glass rod. 

Dry tests a. Blowpipe test All tin compounds when heated with sodium carbonate, preferably in the presence of potassium cyanide, on charcoal give white, malleable and metallic globules of tin which do not mark paper. Part of the metal is oxidized to tin(IV) oxide, especially on strong heating, which forms a white incrustation upon the charcoal. 

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