Liquid substances

Modifications of the simple distillation are described on pp. 23-24 under Purification of Liquid Substances. Fig. 3. 

Emulsion A liquid mixture of two or more liquid substances not normally dissolved in one another, one liquid held in suspension in the other. 

Particulate material consists of solid or liquid substances that may be visible or invisible. The particles affect visibility and can be transported over long distances by wind. The small particles, less than PM, are particularly dangerous to human health as they can pass through nostril hairs (cilia) and enter the lungs. 

All gas mixtures are homogeneous hence all gas mixtures are solutions. Air is an example. There is only one phase—the gas phase—and all the molecules, regardless of the source, behave as gas molecules. The molecules themselves may have come from gaseous substances, liquid substances, or solid substances. Whatever the source of the constituents, this gaseous solution, air, is a single, homogeneous phase. As with other solutions, the constituents of air are separated by phase changes. 

Because of their resistance to chemicai attack, nitrogen atoms are not iocked up in solid or liquid substances as are other eiements such as Si, Ai, Fe, and H. The most stabie form of the eiement nitrogen is a gaseous diatomic moiecuie with a very strong tripie bond. Therefore, the eiement nitrogen is concentrated in the Earth s gaseous atmosphere even though it is oniy a trace eiement in overaii abundance. 

Chemical potential, p, is another name for total internal energy. Convenient units for it are energy per mole. In terms of the work done on (PdV), and the entropy (S) of a gaseous or liquid substance, it may be written in differential form (Callen, 1960) ... 

Most substances have a slightly smaller molar volume as a solid than as a liquid substances generally decrease in volume when they freeze. Water is the notable exception it expands (increases in molar volume) upon freezing. That is why closed containers holding water and other aqueous solutions will break in freezing weather. Although iron is much more dense overall than the compounds in Table 12-1, and its molar volumes are much less than those of benzene and carbon tetrachloride, iron still behaves normally. The molar volume of liquid iron is still greater than that of solid iron. 

Table 6.1 Surface tension or average surface energy of some solid and liquid substances [12, 13].

Vapor pressure—The tendency of a liquid substance to escape the liquid phase and become a gas, or the pressure exerted by the gas molecules of a substance above a liquid containing that substance. 

Regulates the discharge of oil, noxious liquid substances, and garbage generated during the normal operations of vessels, and implements the international treaty on prevention of pollution by ships, known as MARPOL, and prohibits ships from discharging plastic wastes... 

For such cases in which the two forms have been brought to light solely as a result of improved experimental methods, the term tauto-merism " has been modified to desmotropism In desmotropic substances the tautomeric relations are therefore particularly clear and well defined numerous examples have become known, which now also include aceto-acetic ester. The case of acetylacetone is quite similar, but here the formation of the enol-form is much more favoured. The liquid substance contains up to 80 per cent of enol. 

Weight per millilitre is prevalent in the Pharmacopoeia of India for the control of liquid substances, whereas Relative Density (20720°) or Specific Gravity is mostly employed in the European Pharmacopoeia. 

If, then, you would attain the longed-for goal, observe just measure in mixing the liquid substance of the Sages, lest that which is too much overpower that which is too little, and the generation be hindered. For too much rain spoils the fruit, and too much drought stunts its growth. Therefore, when Neptune has prepared his bath, measure out carefully the exact quantity of permanent water needed, and let there be neither too little nor too much. 

Consider two liquid substances that are rather similar, such as benzene and toluene or water and ethylene glycol. When moles of the one are mixed with B moles of the other, the composition of the liquid mixture is given by specification of the mole fraction of one of them [e.g., Xa, according to Eq. (2.2)]. The energy or heat of the mutual interactions between the molecules of the components is similar to that of their self interactions, because of the similarity of the two liquids, and the molecules of A and B are distributed completely randomly in the mixture. In such mixtures, the entropy of mixing, which is a measure of the change in the molecular disorder of the system caused by the process of mixing the specified quantities of A and B, attains its maximal value ... 

Column Chromatography. The main idea here is to dissolve your mixture and put it on the adsorbent, at the top of the column. Then you wash the mixture down the column using at least one eluent (solvent), perhaps more. The compounds of your mixture are carried along by the solvents and washed out of the column at different rates and collected into separate flasks. Why do you want to do this Let us say you have a substance that needs to be purified, but it cannot be distilled because it decomposes at a low temperature, or you wish to extract one of many mixable liquid substances that have been mixed together, etc. A column chromatography can separate, purify and extract. 

Take the terms Fire and Water. In former times all liquid substances were supposed to be liquid because they possessed something in common this hypothetical something was... 

But here is another piece of recent news.. .. It is a new simple body which will find its place between chlorine and iodine. The author of this discovery is M. Ballard of Montpellier. This new body, which he calls muride, is found in sea water. He has extracted it from the mother liquor of Montpellier brines by saturating them with chlorine and distilling. He obtains a dark red liquid substance boiling at 47°. The vapor resembles that of nitrous acid. Its specific gravity is 3. One preserves it under concentrated sulfuric... 

Riot-control agents—such as CS, CN, and CR—are solids. Edge-wood scientists felt that dissemination and decontamination would be simpler with a volatile liquid agent. Research led to the produc tlon and testing of l-methoxy-l,3,5-cycloheptatriene (CHT, EA 4923), a liquid substance of high volatility (Table 4-40) with physiologic effects typical of riot-control agents (e.g., lacrlmation, skin irrl tatlon, and mucous membrane irritation). 

Fats, Fatty Oils, Tallows, Butters, Waxes and Fatty Acids are general terms for greasy, solid or liquid substances occuring in animals and vegetables... 

Fog. Any heterogeneous suspension of droplets of water or other liquid substances in a gas which disturbs its transparency may be called a fog. If the particles in suspension are solid, the fog is usually called smoke or "smog . In Chemical Warfare Service, the term "Smoke is used for both liquid and solid suspensions... 

Solid and liquid substances are not represented in a K, expression, since their concentrations do not vary in the course of reaction. For example,... 

Another use of urea is for resins, which are used in numerous applications including plastics, adhesives, moldings, laminates, plywood, particleboard, textiles, and coatings. Resins are organic liquid substances exuded from plants that harden on exposure to air. The term now includes numerous synthetically produced resins. Urea resins are thermosetting, which means they harden when heated, often with the aid of a catalyst. The polymerization of urea and formaldehyde produces urea-formaldehyde resins, which is the second most abundant use of urea. Urea is dehydrated to melamine, which, when combined with formaldehyde, produces melamine-formaldehyde resins (Figure 96.2). Melamine resins tend to be harder and more heat-resistant than urea-formaldehyde resins. Melamine received widespread attention as the primary pet food and animal feed contaminant causing numerous cat and dog deaths in early... 

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