Chemicals phrases

Students use of diagrams is frequently hmited by their lack of chemical knowledge, their lack of ability to attend to the detail of the diagram and their lack of ability to use chemical terminology accurately, evidenced by the incorrect use of chemical phrases and misuse of everyday language. There are three important facts that need to be imderstood in order to gain a better imderstanding of the sub-micro level ... 

Terms and Phrases used in the Chemical Exposure Treatment Cards (1992)... 

Chemical Process Industry The phrase is used loosely to include facilities that manufacture, handle and use chemicals. 

It is reasonable to expeet that models in ehemistry should be capable of giving thermodynamic quantities to chemical accuracy. In this text, the phrase thermodynamic quantities means enthalpy changes A//, internal energy changes AU, heat capacities C, and so on, for gas-phase reactions. Where necessary, the gases are assumed ideal. The calculation of equilibrium constants and transport properties is also of great interest, but I don t have the space to deal with them in this text. Also, the term chemical accuracy means that we should be able to calculate the usual thermodynamic quantities to the same accuracy that an experimentalist would measure them ( 10kJmol ). 

The context of this work, at least superficially, is quality control in the chemical and pharmaceutical industries. The general principles apply to any form of (chemical) analysis, however, whether in an industrial setting or not. Other readers need only to replace some phrases, such as Health Authority with discriminating customer or official requirements with market expectations, to bridge the gap. The specifically chemical or pharmaceutical nomenclature is either explained or then sufficiently circumscribed so that the essentials can be understood by students of other disciplines. 

Requirements for labelling of containers for supply may differ from those for conveyance. Key features of a supply label are to identify the substance (the chemical name in most cases) and any hazards and safety precuations. In Europe the classification, packaging and labelling of dangerous substances is covered by Directive 67/548/EEC as amended. This requires labels to identify appropriate risk and safety phrases (Tables 12.2 and 12.3) depending upon product properties. A substance is considered dangerous if in Part lA of an approved list or if it exhibits hazardous properties as defined in Schedule 1 for supply, or Schedule 2 for conveyance as shown in Tables 12.4 and 12.5. Substances not tested should be labelled Caution — substance not yet fully tested . Criteria for risk phrases are provided, e.g. as in Table 12.6 for toxic compounds. 

C04-0046. Update your list of memory bank equations. For each equation, add a phrase that describes the kinds of chemical problems for which the equation is used. 

Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances. Annex 1 of the directive assigns Risk Phrases to chemical substances. 

C L (Classification and Labelling), Risk and Safety Phrases, Danger and so on lUCLID (International Uniform ChemicaL Information Database) Chemical Data Sheets, lUCLID Export Files, OECD-IUCLID Export Files, FUSES Export Files... 

Zero emission plants, environmentally benign or green chemistry, and sustainable development have become the catch phrases of the 1990s (Anastas and Farris, 1994 Anastas and Warner, 1998 Anastas and Williamson, 1998 Clark, 1995). Consequently, traditional concepts of process efficiency are changing from an exclusive focus on chemical yields to one that assigns economic value to eliminating waste and avoiding the use of toxic and/or... 

The title was adapted from a phrase coined by Prof. James McKerrow (University of California, San Francisco), as quoted by P. Frost in the American Chemical Society newspaper Chemistry (Spring 1999, 15-19). 

Export processes are often more complicated than the expression given in Equation 7, for many chemicals can escape across the air/water interface (volatilize) or, in rapidly depositing environments, be buried for indeterminate periods in deep sediment beds. Still, the majority of environmental models are simply variations on the mass-balance theme expressed by Equation 7. Some codes solve Equation 7 directly for relatively large control volumes, that is, they operate on "compartment" or "box" models of the environment. Models of aquatic systems can also be phrased in terms of continuous space, as opposed to the "compartment" approach of discrete spatial zones. In this case, the partial differential equations (which arise, for example, by taking the limit of Equation 7 as the control volume goes to zero) can be solved by finite difference or finite element numerical integration techniques. 

This phrase is taken from a letter written by Charles Darwin (1871) that contains vague references to chemical evolution ... if we could conceive in some warm, little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity etc. present that a proteine compound was chemically formed... . 

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