Control
1. What methods are used for separation and purification of substances in technological processes? 2. What physical methods are used for technological processes 3. Describe the basic operating time of obtaining hexamethylenetetramine
APPENDIX Laboratory.work 1 – obtaining hexamethylenetetramine Methods. method (1). To pour 50 ml of formalin in a conical flask, on cooling pour 10 ml of solution ammonia with small portions. Reaction is exothermic, so you need to always monitor the temperature (it should not be higher than 15-18). Next the flask stoppered and to leave for 6-8 hours. During this time the ammonia in the flask should be in excess (to smell ammonia, the reaction to phenolphthalein – alkalinity). After that the liquid is evaporated (boiling avoid) in a water bath until a significant number of crystals and filtered. The crystals squeezed between sheets of filter paper and dried at 30-35 0. Methods. method (2). To introduce 50g of 40% formalin in a flask equipped with a stirrer with a dropping funnel. With cooling and stirring, slowly pour 35g of 25% solution ammonia. After adding solution ammonia, stopper the flask and to leave for 6-8 hours. Then filter the solution having a smell of ammonia. Evaporate under vacuum (at a pressure of 10-15 mm and a temperature of 25-30) until a significant number of crystals. The crystals are filtered and dried in desiccator.
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