Cylinders of compressed gas

Fill A with well-activated charcoal to within 1 to 2 cm. of the overflow tube E. Immerse A in D and conduct in the two gases sulfur dioxide and chlorine, in equal volumes, best from cylinders of compressed gas. Action begins at once with considerable heat evolution, and after a time the union of the gases becomes almost quantitative. The flow of the two gases should be regulated so that the least number of bubbles escapes through the liquid collecting in A. Temperature is of... 

The ether solution is filtered through a dry filter paper into a 5-I. round-bottom flask which is fitted with an efficient mechanical stirrer and immersed in an ice-salt bath. When the temperature of the solution has fallen to o° (Note 2), a rapid stream of dry ammonia gas, from a cylinder of compressed gas, is passed into the solution. 

Compressed gas cylinders. Under certain circumstances, cylinders of compressed gas may constitute major explosion and fire hazards and, despite their apparent robust construction, they should always be handled with care.7... 

A cylinder of compressed gas has a volume of 14.5 L and a pressure of 769 kPa. What volume would the gas occupy if it were allowed to escape into a balloon at a pressure of 117 kPa Assume constant temperature. 

A good example of this molecule-pressure relationship may be observed in an ordinary cylinder of compressed gas equipped with a pressure gauge. When the valve is... 

The driving force producing mobile phase flow in GC is simply the cylinder of compressed gas dehvered via a pressure regulator, although modern electronic flow controls introduce a useful level of sophistication (Hinshaw 2002b). However, HPLC pumps must provide a continuous constant flow of the eluent through the injector, colnmn and detector, and are a crucial component of any HPLC system (Kazakevich 1996). 

Chemica.1 Properties. Reviews of carbonyl sulfide chemistry are available (18,23,24). Carbonyl sulfide is a stable compound and can be stored under pressure ia steel cylinders as compressed gas ia equiUbrium with Hquid. At ca 600°C carbonyl sulfide disproportionates to carbon dioxide and carbon disulfide at ca 900°C it dissociates to carbon monoxide and sulfur. It bums with a blue flame to carbon dioxide and sulfur dioxide. Carbonyl sulfide reacts... 

It is also desirable to spot test the instrument s response between calibrations. For this purpose, several suppliers of compressed gas prepare cylinders containing almost any desired concentration of the gas or vapor of interest. If it is not practical... 

It is obvious that the flow rate must be precisely controlled. The pressure from the compressed gas cylinder of carrier gas, while sufficient to force the gas through a packed column, does not provide the needed flow control. Thus a flow controller valve is built into the system. The flow rate of the carrier gas, as well as other gases used by some detectors, must be able to be carefully measured so that one can know what these flow rates are and be able to optimize them. Flow meters are commercially available. However, a simple soap bubble flow meter is often used and can be constructed easily from an old measuring pipet, a piece of glass tubing, and a pipet bulb. See Figure 12.10. With this apparatus, a stopwatch is used to measure the time it takes a soap bubble squeezed from the bulb to move between two graduation lines, such as the 0- and 10-mL lines. The commercial version uses an electronic sensor to measure the flow rate based on the bubble movement. See Workplace Scene 12.3. 

B. Safe Delivery Of Gases. The vast majority of compressed gas cylinders are supplied with efficient on-off valves which provide no significant flow or pressure control. CAUTION It Is necessary to eqnip a compressed gas cylinder with some means of controlling the pressure and/or flow of the gas being deltv-... 

The first level of safety for quality and control is the construction of compressed gas cylinders. The specifications for their construction in North America is defined by Department of Transportation (DOT) and Canadian Transport Commission (CTC) regulations. Cylinders are made from carbon steel or alloy steel with seamless, brazed, or welded tubing that is formed by billeting (drawing flat... 

This type of sprayer consists of a sealed container of compressed gas and pesticides. The pesticide is driven through an aerosol-producing nozzle when the valve is activated. Pressurized cans usually have a capacity of less than one quart (one liter) and are not reusable. Larger reusable cylinders are available for structural pest control and for some greenhouse uses. Figure 8.1 depicts an aerosol can containing an insecticide under pressure... 

The same high sensitivity that makes measurements so convenient causes great difficulty in the electrolytic industry. Thus, it takes 9.65x10 C or 26.8 A h to generate one equivalent of a product formed by electrolysis. A cylinder of compressed contains about a pound of the gas. It would take a water electrolyzer running at 10 A about 12 hours to produce this small amount of hydrogen ... 

The valves of a cylinder of oxygen should be set to deliver gas at a pressure of 10 Ib/sq in. when the terminal valve is opened. The barrel of a 2.5-mL plastic syringe is cut off and thrust into the end of a i x -in. rubber delivery tube. Read about the handling of compressed gas cylinders in Chapter 2. Be sure the cylinder is secured to a bench or wall. 

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