Water, boiling

For purification, transfer the acid to a 150 ml. flask containing 60 ml. of water, boil the mixture under reflux, and then add acetic acid in 5 ml. portions down the condenser until almost all the solid has dissolved avoid an excess of acetic acid by ensuring that the solvent action of each addition is complete before the next portion is added. A small suspension of insoluble impurity may remain. Add 2 g. of animal charcoal, boil the solution again for 10-15 minutes, and then filter it through a preheated Buchner funnel. Cool and stir the filtrate, which will deposit pale cream-coloured crystals of the acid. Collect as before and if necessary repeat the recrystallisation. Yield of pure acid, 9 g. m.p. 227-229°. 

Place a mixture of 1 0 g. of the hydrocarbon, 10 ml. of dry methylene chloride or ethylene dichloride or syw.-tetrachloroethane, 2 5 g. of powdered anhydrous aluminium chloride and 1-2 g. of pure phthalic anhydride in a 50 ml. round-bottomed flask fitted with a short reflux condenser. Heat on a water bath for 30 minutes (or until no more hydrogen chloride fumes are evolved), and then cool in ice. Add 10 ml. of concentrated hydrochloric acid cautiously and shake the flask gently for 5 min utes. Filter oflf the solid at the pump and wash it with 10-15 ml. of cold water. Boil the resulting crude aroylbenzoic acid with 10 ml. of 2 -5N sodium carbonate solution and 0 2 g. of decolourising carbon for 5 minutes, and filter the hot solution. Cool, add about 10 g. of crushed ice and acidify... 

To prepare the hydrochloride, dissolve about 1 g. of the compound (which need not be perfectly dry) in about 8 ml. of alcohol. Add this solution to boiling dilute hydrochloric acid (10 ml. of the concentrated acid and 80 ml. of water). Boil for 5 minutes, filter the hot solution if necessary, and allow to cool. p-Amino-azobenzene hydrochloride separates in steel-blue crystals. Filter, wash with a little dilute hydrochloric acid, and dry. 

Beckmann rearrangement of benzophenone oxime to benz-anilide. Dissolve 2 g. of benzophenone oxime in 20 ml. of anhydrous ether in a small conical flask and add 3 g. of powdered phosphorus pentachloride (or 3 ml. of pure tbionyl chloride). Distil off the solvent and other volatile products on a water bath CAUTION ether), add 25 ml. of water, boil for several minutes and break up any lumps which may be formed. Decant the supernatant liquid, and recrystallise, in the same vessel, from boiling alcohol. The product is benzanilide, m.p. 163° confirm this by a mixed m.p. determination with an authentic specimen. 

Tricarballylic acid. Place 228 g. (204 ml.) of ethyl propane-1 1 2 3-tetracarboxylate and 240 ml. of 1 1 hydrochloric acid in a 1-litre threenecked flask, fitted with a mechanical stirrer and a fractionating column with condenser set for downward distillation attach a receiver with side tube to the condenser and connect the side tube to a wash bottle containing water. Boil the mixture, with continual stirring, at such a rate that the... 

AH gg = —43.03 kJ/mol ( — 10.28 kcal/mol) including heat of solution, at standard state m = V) and may require a heat sink to prevent boiling of the reaction mixture. A 30% by weight suspension of MgO in 20°C water boils in the absence of any heat sink. The time to reach boiling is dependent on the reactivity of the MgO raw material, and this time can be only several hours for the more reactive grades of MgO. Investigations of the kinetics of formation of magnesium hydroxide by hydration of MgO have been reported (79). 

The agar-based impression materials are used extensively for dupHcating casts. Frequendy, it is desired to retain the original model for reference and do the actual work on a dupHcate cast. Partial-denture fabrication requires that the original stone cast be dupHcated in an investment. For dupHcating, the agar-based impression material is usually diluted with water, boiled, cooled to the desired temperature, and carefully poured over the model to be dupHcated. 

The crude acid is dissolved in 300 cc. of hot water, boiled with 4-5 g. of decolorizing charcoal for a few minutes, and the solution filtered. After cooling thoroughly under the tap the purified product is filtered with suction and washed with 10-15 c. of cold water. The purified acid weighs 35-40 g. (70-80 per cent of the theoretical amount) and melts at 211-212°. 

Vaporization cavitation repre.sents about 70% of all cavitation. Sometimes it s called classic cavitation . At what temperature does water boil Well, this depends on the pressure. Water will boil if the temperature is high enough. Water will boil if the pressure is low enough. 

The maximum attainable production was sought that did not cause thermal runaway. By gradually increasing the temperature of the water, boiling under pressure in the reactor jacket, the condition was found for the incipient onset of thermal instability. Runaway set in at 485.2 to 485.5 K for the 12 m reactor and at 435.0 to 435.5 K for the shorter, 1.2 m reactor. The smaller reactor reached its maximum operation limit at 50 K lower than the larger reactor. The large reactor produced 33 times more methanol, instead of the 10 times more expected from the sizes. This... 

Boiling - This involves bringing the water to its boiling point in a container over heat. The water must be maintained at this temperature 15 to 20 minutes. This will disinfect the water. Boiling water is an effective method of treatment because no important waterborne diseases are caused by heat-resisting organisms. 

The BWR operates at a pressure such that cooling water boils as it passes through the core the steam is dried, exits containment and drives the turbine-generator to produce electricity. This direct cycle is like a fossil-burning power plant. 

Tyrosine.—On cooling, a brown, crystalline crust of impure tyrosine separates. It is filtered, dissolved in the least quantity of boiling water, boiled with a little animal charcoal, and filtered. Oit cooling, long, white, silky needles of tyrosine arc deposited. Yield. rborit 2 grams. 

Water boils at a much higher temperature than would be expected based solely on its molecular weight. The reason is that liquid water exhibits a highly structured network of hydrogen bonds. 

There are three potential types of OTEC power plants opcii-cyclc, closed-cycle, and hybrid systems. Open-cycle OTEC systems exploit the fact that water boils at temperatures below its normal boiling point when it is under lower than normal pressures. Open-cycle systems convert warm surface water into steam in a partial vacuum, and then use this steam to drive a large turbine connected to an electrical generator. Cold water piped up from deep below the oceans surface condenses the steam. Unlike the initial ocean water, the condensed steam is desalinated (free of salt) and may be collected and used for drinking or irrigation. 

Rumford decided to try a more controlled experiment. He placed a brass gun barrel in a wooden box containing about nineteen pounds of cold water, and used a team of horses to rotate a blunt steel borer inside the barrel. After 2.5 hours, the water boiled As Rumford described it, It would be difficult to describe the surprise and astonishment expressed on the countenances of the bystanders on seeing so large a quantity of cold water heated, and actually made to boil, without any fire. ... 

The pump selected for this application (water boiling at 0.98 psia) must have a required NPSH less than 4.7 ft, preferably about 3 to 3.5 ft. This is a difficult condition. If possible the vessel should be elevated to make more head (S) available, which wll raise the available NPSH. 

In this case water boils at approximately 40 F (4.4 C), thereby cooling the chilled water circulating through... 

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