Glass cooling

Fig. X-14. SEM picture of a drop ot cooled glass on Femico metal (which has the same coefficient of thermal expansion). xl30. (From Ref. 183.)...

Ma.nufa.cture. The preparation of sulfuryl chloride is carried out by feeding dry sulfur dioxide and chlorine into a water-cooled glass-lined steel vessel containing a catalyst, eg, activated charcoal. Alternatively, chlorine is passed into Hquefted sulfur dioxide at ca 0°C in the presence of a dissolved catalyst, eg, camphor, a terpene hydrocarbon, an ether, or an ester. The sulfuryl chloride is purified by distillation the commercial product is typically 99 wt % pure, as measured by ASTM distillation method D850. 

The use of a water-cooled glass condenser is not recommended since it might accidentally be broken and thereby cause water to flow into the flask. A metal water-cooled condenser has also been used and is satisfactory. 

Use caution and the proper equipment when handling hot apparatus or glassware. Hot glass looks the same as cool glass. 

I eat is energy that is being transferred from a hot object to a colder object. If you know how much heat a substance can absorb and hold, the amount of energy transferred between two substances can be determined. On a hot, sunny day, heat from the Sun might go into a cool glass of lemonade and melt the ice. On a cold winter day, heat may leave a hot cup of coffee and warm up the air around it. In this lab, specific heat is used to follow the flow of energy and to determine the temperature of a Bunsen burner flame. 

When mixed with sodium carbonate (soda ash) and calcium carbonate (powdered limestone) and heated until the mixture melts, silica (sand) forms glass when cooled. Glass of all types has near limitless uses. One example is Pyrex, which is a special heat-resistant glass that is manufactured by adding boron oxide to the standard mixture of silica, soda ash, and limestone. Special glass used to make eyewear adds potassium oxide to the above standard mixture. 

Preparation of Normal Ammonium Tungstate. Weigh 0.5 g of tungstic acid in a test tube, put the latter into a cooling mixture (solid carbon dioxide with acetone), and pour in 1-2 ml of liquid ammonia. Stir the contents of the test tube with a cooled glass rod and let the ammonia evaporate. Examine the precipitated crystals under a microscope. What is the composition of the product ... 

This compound is formed by thermal splitting of tetra-sulfur tetranitride. The apparatus is shown diagrammat-ically in Fig. 15. The tube A is 320 mm. long and made of quartz. The diameter of the lower half is 11 mm., that of the upper part about double. C is a water-cooled "glass finger. The quartz tube is heated by the two ovens, Hi and Hi should produce a temperature of 80°, while H2... 

Glass expands as it gets hot. The effects of expansion of solid materials are well demonstrated with the ring-and-ball demonstration. In this demonstration, a ring is unable to get past a ball on the end of a rod. If the ring is heated just a small amount, it expands sufficiently to easily slide past the ball. In a similar fashion, a warm glass container holds more liquid than a cool glass container. 

A solution of the unsaturated compound in CHCf, (15% v/v) was placed in a water-cooled glass reactor, and CIF was passed through in the dark at a rate of 23 L h for the time corresponding to the absorption... 

Vapors in contact with cool glass condense to form pure liquid distillate. 

From these examples it will be clear that the stress in a cooled glass rod, prevented from contracting, depends on the magnitude of the fraction of the total length cooled and on the amount of cooling. 

Covalently bonded solids such as quartz, diamond, and graphite form another class of crystals. Quartz is a continuous network of silicon dioxide bonded in a uniform, crystalline arrangement. Sand is a mixture of quartz and other rocks. Glass is solid quartz that has melted and resolidified without the same crystalline uniformity, in the way that melted butter does not re-form the same type of solid when it cools. Glass has been known to form naturally in lightning strikes on sand. 

Figure 7.15. Observed and simulated "B MAS NMR spectra of A. (Na20)o.o5(B203)o.95 and B. (Na20)44.5(B203)i 1(8102)44.5 slow-cooled glasses showing the individual simulated BO3 and BO4 sites. The spectra of the corresponding faster-cooled glasses show similar details. From Sen et al. (1998), by permission of Elsevier Science.

In a typical experiment 80 mg of FS03H was introduced into a dry clean proton NMR tube at -115° followed by condensation of SOjCIF ( 0.35 ml). With the aid of a cooled glass rod 30 mg of precursor was introduced and the resultant mixture homogenized. Appropriately larger amounts were used for the 13C NMR than for the H NMR spectra. Immediately after the generation of the cations the samples were inserted into the precooled NMR probe. The temperatures at which the spectra were recorded were measured using... 

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