Chemical glassware

Soda-lime glass Borosilicate glass 70 SiOj, 10 CaO, 15 Na O 80 SiOj, 15 BjOj, 5 NajO Windows, bottles, etc. easily formed and shaped. Pyrex cooking and chemical glassware high-temperature strength, low coefficient of expansion, good thermal shock resistance. 

The Hagberg Falling Number test only just qualifies for this section as it is an effective way of measuring the a-amylase activity of wheat or flour. It has the considerable advantage that it is unaffected by any added fungal a-amylase. In addition, it only requires a supply of distilled water and electricity - there is no need for chemical glassware or any reagents. 

Consider in advance the work to be undertaken - plan what is needed in terms of chemicals, glassware, movement about the laboratory, and specific training. Include a plan for what to do in the event of something going wrong. 

Calibration of chemical glassware at plants manufacturing expls, etc 2 C6... 

Calibration of Chemical Glassware at Plants Manufacturing Explosives and Related Items. 

There are two minor papers that deal with the practice of chemistry at the University of Edinburgh in the latter half of the 18th century, one concerning the availability and manufacture of chemical glassware (an under-studied topic)21 and the second with the supply of heat sources in laboratories (also under-studied) and, in particular, with the new form of chemical furnace designed by Joseph Black (1728-1799).22 Though once very widely used, no original form of the furnace appears to have survived. This is a typical example of the poor survival rate, which may well be a factor in the paucity of papers on chemical apparatus. 

Besides such electrical applications as water-repellent surface films, there are many applications where water repellency is an end in itself. Treated glass windowpanes or windshields are not wet by muddy water, and so they stay clean longer and are easier to clean whenever washing is required. Rain docs not flood the surface of a treated windshield but stands in small droplets when the car is in motion the air stream blows the droplets off, leaving the glass clear. Treated tumblers are easier to wash and dry treated chemical glassware holds water with a flat meniscus treated vitreous enamel does not stain easily and has improved luster. Cloth and paper may be made water-repellent for protection against rain, and it is possible that all clothes could be so treated. 

The extreme sensitivity of RNA to the ubiquitous inter- and intracellular nudeases (for example on the skin of the investigator) makes special precautions necessary for effective RNA preparations. The use of disposable containers is recommended, or glassware that has been soaked in dilute hydrochloric acid and rinsed with autoclaved distilled water. Disposable gloves must be worn in all procedures where RNA is handled, or is likely to come into contact with RNA, such as solutions, chemicals, glassware, spatulas etc. Buffers for RNA work should be prepared from reagents reserved for this purpose, and stored separately. Buffers can be treated with 0.2 % (v/v) diethylpyrocarbonate (care - this is carcinogenic) and autodaved to inactivate RNases, or at least those with adive site histidines. Since most nucleases require Mg2 for activity, the addition of EDTA in mM concentrations to solutions is also recommended. 

Rubbery Aromatic characteristic of old rubber. Rubber stoppers used for chemical glassware... 

This is the list of alternative, retail laboratory supply companies. These are the sisters and brothers of the companies in the main list that absolutely sell to individuals. These are small, retail outlets that sell chemicals, glassware and equipment. But for some reason or another they just didn t make it to the A list. 

Next, the temperature of the mixture is brought up to the correct level. For butyl nitrite, the temperature of 550C is reached by using hot water, steam, or heating tape. If a wine jug is the reaction vessel, care is used in rapid and uneven heating, as this could crack the glass. This is the reason why chemical glassware is made of Pyrex. 

Perform your analytical procedure without the components. Calculate the results as if the same test portion as in your sample determination were taken for analysis. Please correct the results for the sample if appropriate for the blank. Please, remember that very high reagent blanks are revealing the use of inappropriate chemicals, glassware or methods. Action should be taken in case such blanks occur to find the contamination source. ... 

A small fire clay crucible of about 25 c.c. capacity is a useful little article to have about the laboratory and it is capable of standing much higher temperatures than ordinary glassware, and for this reason it can be used where ordinary chemical glassware would be unsuitable. 

This is about the most complicated procedure used in making any of the nitric esters. If you feel confused when reading this, do not be discouraged. Many of the better explosives are made much more simply. The only special piece of chemical glassware that would come in handy for this preparation is a separatory funnel (unless distillation of the crude product is attempted - DANGER ). A good eyedropper can replace the separatory funnel in this procedure. I ll explain how in the text. 

There are more than a few distressing aspects, however, to obtaining and possessing such nice chemical glassware. Due to the widespread success of my drug manufacture books. 

An antifreeze distillation using this setup will proceed in the same manner as described for the chemical glassware version, with the difference that it will not be possible to as closely monitor the process. With some practice, and using the same brand of antifreeze, it should be possible to get as good results using this apparatus as with the chemical glassware. 

Finally, some support must be provided for the copper tubing so that its weight does not cause the metal can to tip over, or cause damage to the cork. Any type of support is OK for this purpose, so long as it does the job. This requirement for support is not unique to the homemade still, as the chemical glassware set-ups also need clamping into place or other measures to hold the pieces together. 

Doing a distillation using this homemade still works almost exactly the same as with chemical glassware. There are only two areas where the method differs. The first difference is that the thermometer inserted into the top of the can will measure the... 

The laboratory equipment of the fluorine chemist is unusual in that ordinary chemical glassware cannot be used in most cases. Apparatus made of nickel, iron, copper, lead, silver, platmum, fluorspar or sintered alumina is used instead. Where transparency is indispensable, quartz equipment is utilized. 

Fig. 264 shows Brauer s apparatus for distilling Cs and Rb. Ordinary chemical glassware may be used. (However, according to Hevesy and Ldgstrup, distillation of potassium requires Pyrex apparatus.) Tube B is slightly inclined. The ampoules are... 

Chemical glassware is sufficiently resistant to concentrated alkali hydroxide solutions at room temperature that it can be used without adversely affecting the purity of the products. However, hot, concentrated alkali hydroxide solutions attack any glass so strongly that the latter can be used at high temperatures only for short periods of time, if at all. Such experiments must therefore be run in refined silver containers, which resist even concentrated boiling alkali hydroxide solutions. While pure nickel containers are also suitable, they are not cheaper than silver. 

The possession of chemical glassware by someone not involved in the chemical field... 

In 1996, the District of Columbia vigorously attacked the Army Corps of Engineer s conclusion of no further action in that same Final Report on the World War I Poison Gas Production at the AUES. Since then, the District s main contentions— that there were significant quantities of munitions, chemical glassware, and arsenic contamination remaining— have been proven to be 100 percent correct. 

Scores of volatile compounds have been detected on two of these properties. Arsenic at a level of 2400 ppm has been found adjacent to one of these properties. A small disposal area of chemical glassware was excavated about 100 ft from one of these properties with surface arsenic levels at 3350 ppm. 

As noted previously, the District of Columbia surveyed the adjacent American University area and found several anomahes. The Corps surveyed portions of American University and found 600 anomalies. Excavation on a portion of Lot 18 on the American University campus has confirmed 30 shells to date with a burn pit of debris including six 50-gal drums of chemical glassware. Thirty bottles—one containing Lewisite— have also been found. Some residents have reported health problems to the ERA, including the resident that testified before the City Council. 

During the arsenic sampling, the District of Columbia found a pit of chemical glassware. They asked the Corps to remove the items, which they did. Arsenic on the surface soil was 3350 ppm. The District thrai asked the Corps to conduct a geophysical survey of several areas on the American University campus. Several disposal pits and empty shells have been found. 

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