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(3) The copolymer, when extracted with n-hexane at reflux temperature for 2 hours, yields total extractives not to exceed 0.05 percent. [ 42 FR 14572 , Mar. 15, 1977; 49 FR 5748 , Feb. 15, 1984, as amended at 55 FR 34555 , Aug. 23, 1990]
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2. For casein or gelatin, carefully heat the mixture under reflux for 35 minutes using a heating mantle or a very small flame. For hair or silk, heat the mixture under reflux for 50 minutes. 3. After the reflux period is completed, the hydrolysate must be decolorized. Add about 0.5 g of decolorizing carbon to the hot hydrolysate and swirl the ...
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A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity.Differential scanning calorimeters, isothermal micro calorimeters, titration calorimeters and accelerated rate calorimeters are among the most common types. A simple calorimeter just consists of a thermometer attached to a …
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fig A Reflux apparatus fig B Distillation apparatus This practical procedure is best carried out over two lessons if the students have not previously used Quickfit apparatus. Alternatively, you may use an electric heating mantle to heat the flask containing the reflux mixture.
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heat the flask to a gentle reflux using a setting of about 60 on the rheostat. Again, the exact setting depends on the size of the heating mantle, etc. Do not heat too quickly as the reaction can get out of control and HBr gas can escape. If you do see HBr gas escaping immediately lower the heating mantle from the flask and call for
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heated using a heating mantle and provided with a reflux condenser discharging into a trap connected to the flask. The trap serves to collect and measure the condensed water and to return the condensed solvent to the flask (See figures below) and a copper wire long enough to extend throughout the condenser with one end twisted into a spiral. The
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Jan 21, 2014 First, heating the single 3 L reaction flask (Figure 1B), will result in condensation of water vapor onto the tips of the electrodes, dampening the spark, and reducing the generation of radical species that drive much of the chemistry taking place within the experiment. Furthermore, the use of a heating mantle to heat the apparatus is not ...
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The Florence flask is a hybrid between the round bottom and the Erlenmeyer flask and ranges from a few hundred milliliters to a few liters in size. Florence flasks can have either a flat bottom or a round bottom, so applications vary from direct heating to using a heating mantle.
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The sixth book in the #1 New York Times bestselling Field Party series—a Southern soap opera with football, cute boys, and pick-up trucks—from USA TODAY bestselling author Abbi Glines. Ezmita Ramos has always had big plans for her future, ones that would take her far outside the Lawton city limits. But with overprotective parents who control every part of her life, she’s …
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The term reflux means heating a liquid to boiling and condensing the vapors back into the flask. True. For the condenser, the bottom tube should be connected to the water source, the upper tube placed into the drain ... If a student needs to heat things over 100 C, then a heating mantle should be used. True. Magnetic stirrers provide ...
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Turn on the heating mantle to achieve a gently boiling of the reaction mixture. Reflux the mixture for 30 minutes. Turn off the heat and allow the mixture to cool. Note: your round bottom flask now contains some ester (the desired product), as well as water, unreacted alcohol, unreacted carboxylic acid, and sulfuric acid.
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While heating, it’s essential to hold the test tube at a 45-degree angle so that the gases formed inside the narrow tube may easily escape without causing the hot liquid to shoot up. Boiling Tube A boiling tube is a glassware apparatus that looks similar to …
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Working safely with hazardous chemicals requires proper use of laboratory equipment. Maintenance and regular inspection of laboratory equipment are essential parts of this activity. Many of the accidents that occur in the laboratory can be attributed to improper use or maintenance of laboratory equipment. This chapter discusses prudent practices for handling …
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