Carbon dioxide dry ice

Solid carbon dioxide (Dry Ice, Drikold) is employed when very low temperatures are required. If it is suspended in solvents, such as alcohol or a mixture of equal volumes of chloroform and carbon tetrachloride, temperatures down to — 50° can be easily attained. Lower temperatures still are reached if intimate mixtures of solid carbon dioxide and organic solvents are employed with ethyl alcohol, — 72° with... 

The gas is dried by passage through wash bottles containing concentrated sulphuric acid. Alternatively and more simply, the technique (described below for n.valeric acid) utilising solid carbon dioxide (Dry Ice or Drikold) may be employed. 

Alternatively, the solution of the Grignard reagent may be poured on to solid carbon dioxide (Dry Ice)—for experimental details, see under n-Valeric Acid, Section 111,84. 

Sodamide. Assemble the apparatus shown in Fig. VI, 16, 1, a. Fill the bath to a point about half-way up the side of the flask with methyl alcohol (or methylated spirit) and add solid carbon dioxide (Dry Ice or Drikold) in lump form until a white frost commences to form on the outside of the bath (2) the bath temperature should be about — 35 . 

Dry Ice. Refrigeration of foodstuffs, especially ice cream, meat products, and frozen foods, is the principal use for soHd carbon dioxide. Dry ice is especially useful for chilling ice cream products because it can be easily sawed into thin slabs and leaves no Hquid residue upon evaporation. Cmshed dry ice may be mixed directly with other products without contaminating them and is widely used in the processing of substances that must be kept cold. Dry ice is mixed with molded substances that must be kept cold. For example, dry ice is mixed with molded mbber articles in a tumbling dmm to chill them sufficiently so that the thin flash or rind becomes brittle and breaks off. It is also used to chill golf-ball centers before winding. 

To reduce the amount of dust produced, water can be added to the abrasive from a circular water sprayer around the no22le. Chemical corrosion inhibitors must be dissolved in the water to prevent flash msting of the steel. Newer methods to reduce dust include the use of ice, soHd carbon dioxide (dry ice), or plastic beads as abrasives. Blasting with dry ice is inexpensive and effective, but the accumulation of carbon dioxide must be avoided in enclosures. Plastic beads are inexpensive, but the cutting efficiency is low and paint removal is slow the beads can be cleaned of paint particles and reused. 

Large fragments were scattered in a circle of approximately 400 m (13(X) ft) radius. A shell of 28(X) kg (6000 lb) landed at a distance of 150 m (500 ft), and a fragment weighing 1000 kg (2200 lb) landed 250 m (820 ft) away. A large amount of carbon dioxide was released, causing the immediate vicinity of the yard to be covered with solid carbon dioxide (dry ice). 

The transport of perishables by air does not require mechanical refrigeration, as low temperatures prevail at the heights flown. Fresh vegetables and flowers need to be protected from freezing, and produce will usually be in insulated containers. A feature of this traffic is the prompt and speedy handling at the airports. Coldrooms are provided at some airports to store produce immediately before and after transit. Solid carbon dioxide ( dry ice ) is used for shortterm cooling of airline passenger meals. 

Iodine sublimes more readily than ice because its triple-point pressure, 90 mm Hg, is much higher. Sublimation occurs on heating (Figure 9.6) below the triple-point temperature, 114°C. If the triple point is exceeded, the solid melts. Solid carbon dioxide (dry ice) has a triple-point pressure above 1 atm (5.2 atm at — 57°C). Liquid carbon dioxide cannot exist at 1 atm pressure regardless of temperature. Solid C02 always passes directly to vapor if allowed to warm up in an open cantainer. 

Elemental iodine, I2, is a purphsh solid. Like solid carbon dioxide (dry ice), iodine sublimes. That is, it goes directly from the sohd to the gas phase without ever becoming liquid. So a bottle of iodine has a nice purple haze above the solid element. 

For some purposes solid carbon dioxide ( dry-ice ), sublimation temperature —78.5 °C or mixtures of dry-ice and acetone (temperature —78 to —95 °C) are used as coolants. These are obviously not as efficient as liquid nitrogen and they should not be used with chemicals which have an appreciable vapour pressure at the appropriate temperatures. 

Preparation of Chlorine by Oxidizing Hydrochloric Acid with Potassium Permanganate. Liquefaction of the Chlorine. Assemble an apparatus as shown in Fig. 54. Spill 10-15 g of potassium permanganate into flask 1. Pour a 37 % hydrochloric acid solution into dropping funnel 2, a saturated sodium chloride solution into cylinder 5, and a little concentrated sulphuric acid into wash bottle 4. Put the end of the gas-discharge tube of the apparatus into test tube 5 cooled outside by solid carbon dioxide (dry ice) wetted with acetone. What is the boiling point of chlorine ... 

Fig. 81. Fill two-neck bottle 1 up to one-fourth of its volume with a granulated alkali (IV/ten working with an alkali, wear eye protection Handle the alkali only with pincers ) Pour a concentrated ammonia solution into dropping funnel 2. Pour vaseline or paraffin oil (a bubble counter) into wash bottle 3. Put a granulated alkali into drying column 4. What substances should be used for drying ammonia Fasten a dry bottle over gas-discharge tube 6. When you have assembled the apparatus, put solid carbon dioxide ( dry ice ) into...

Table 16. TEMPERATURE OF COOLING MIXTURES CONSISTING OP SOLID CARBON DIOXIDE (DRY ICE) AND SELECTED SUBSTANCES AT 1 ATM...

The gaseous phase of any material occupies significantly more volume than either its solid or liquid phase, (a) Solid carbon dioxide (dry ice) is broken up into powder form, (b) The powder is funneled into a balloon, (c) The balloon expands as the contained carbon dioxide becomes a gas as the powder warms up. 

Refrigerants. Solid carbon dioxide (dry ice) is used for refrigerating ice cream, meat and soft fruits. It... 

An ice chest containing solid carbon dioxide (Dry Ice) was left open and the inside warmed to room temperature. When examined later, there was no solid and no liquid on the bottom of the chest. What happened to everything ... 

C Solid carbon dioxide (dry ice) has innumerable uses in industry and in research. Because it is easy to manufacture, the competition is severe, and it is necessary to make dry ice very cheaply to be successful in selling it. In a proposed plant to make dry ice, the gaseous CO2 is compressed isothermally and essentially reversibly from 6 psia and 40°F to a specific volume of 0.05 ft3/lbm. 

Why is it that when you buy ice cream from a vendor in a park on a hot summer day, the ice cream wrapper is not soaked with water from the ice that is used to keep it cold Is the vendor using ice at all Dry ice is the term for solid carbon dioxide. Dry ice can change from the solid phase right to a gas phase, without any apparent liquid phase in between. This process is called sublimation. Some other substances that can sublime are mothballs (naphthalene) and solid iodine. Deposition can be thought of being the opposite of sublimation. In this process a gas will form a solid, again without any apparent liquid phase in between. 

The object of the experiment described below is to set up a gas thermometer, calibrate it at the ice point (in lieu of the experimentally more difficult triple point), and use it to determine the temperatures of one or more other fixed points. These may include the steam point, the boiling point of liquid nitrogen, the sublimation temperature of solid carbon dioxide (Dry Ice), the transition temperature of sodium sulfate decahydrate to the monohydrate and saturated solution, etc. The experiment will be performed with an apparatus that... 

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