How to Find Physical Properties of Chemical Substances


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How to use print and internet resources to find physical and thermodynamic properties of substances

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How to Find Physical Properties of Chemical Substances

  2. 2. The Importance of Physical and Thermodynamic Property Data <ul><li>Physical and thermodynamic property data are of value to chemists in academia and industry.  Chemists  often need this data to identify substances they have synthesized or isolated from a biological or environmental sample.  The engineering design of process equipment often requires knowledge of properties such as heat capacity, enthalpy, density, viscosity, and thermal conductivity. </li></ul>
  3. 3. The Importance of Physical and Thermodynamic Property Data <ul><li>Physical property for chemicals especially little-studied substances may be very difficult to find.  The aim of this tutorial is to show you how to use electronic and traditional print resources to find data of interest. This tutorial will also discuss how information moves from the scientist who creates it to the person who needs it. </li></ul>
  4. 4. Flow of Scientific Information
  5. 5. Data Compilations <ul><li>A data compilation ,  in print or electronic format, extracts selected pieces of information from the journal literature.  They are usually limited to type of compound ( i.e. organic, inorganic) or type of property (i.e. thermodynamic, spectral).  A searcher may have to use several data compilations to find the desired information.  On the other hand information on common substances may be found in several sources. Values may conflict. </li></ul>
  6. 6. Data Compilations <ul><li>No single data compilation can contain all published information on the over 20 million unique chemical substances that have been reported in the literature.  </li></ul>
  7. 7. Characteristics of Data Compilations <ul><li>Limited number of substances covered </li></ul><ul><li>Limited by type of compound </li></ul><ul><li>Selected properties only </li></ul><ul><li>Available in electronic and/or print formats </li></ul><ul><li>Critically evaluated? (Values may differ) </li></ul>
  8. 8. Some Print Data Compilations <ul><li>CRC Handbook of Chemistry and Physics (Ready Ref QD65 .C4) </li></ul><ul><li>NIST-JANAF Thermochemical Tables (Ref QD511 .N57 1998) </li></ul><ul><li>International Critical Tables (Ref Q199 .N32) </li></ul><ul><li>Thermodynamic Properties of Individual Substances (Ref QD504 .T43713 1989) </li></ul><ul><li>Thermochemical Data of Organic Compounds (Ref QD511.8 .P43 1986) </li></ul><ul><li>Lange's Handbook (Ready Ref QD65 .L36 1999) </li></ul><ul><li>Merck Index (Ready Ref RS51 .M4 2001) </li></ul><ul><li>Perry's Chemical Engineer's Handbook (Circ Desk TP151 .P45 1997) </li></ul>
  9. 9. Scifinder Scholar <ul><li>Electronic Version of Chemical Abstracts (1907 to the present) </li></ul><ul><li>It contains many links to full-text articles </li></ul><ul><li>Searchable by chemical substance , reaction, research topic, author or affiliation </li></ul><ul><li>Some physical property data is available </li></ul><ul><li>It is now accessible from a web site. </li></ul><ul><li>The desktop version is still available </li></ul>
  10. 10. Scifinder Scholar to find Physical Property Data <ul><li>You can search under compound name or Registry Number </li></ul><ul><li>Click on Microscope Icon </li></ul><ul><li>Some physical property data will be listed </li></ul><ul><li>Some links to the original journal article with the data will be given </li></ul>
  11. 11. CRC Handbook of Chemistry and Physics <ul><li>The most heavily used sources of physical property data.  It is revised annually and also includes mathematical tables, nomenclature rules, symbols, and terminology.  Physical property data is limited to the compounds most frequently encountered in the laboratory, the workplace and the environment.  </li></ul>
  12. 12. CRC Handbook of Chemistry and Physics <ul><li>MOLECULAR WEIGHT </li></ul><ul><li>COLOR </li></ul><ul><li>CRYSTALLINE FORM </li></ul><ul><li>BOILING POINT </li></ul><ul><li>MELTING POINT </li></ul><ul><li>DENSITY </li></ul><ul><li>INDEX OF REFRACTION </li></ul><ul><li>ENTHALPY OF FORMATION </li></ul><ul><li>GIBBS FREE ENERGY </li></ul><ul><li>ENTROPY </li></ul><ul><li>HEAT CAPACITY </li></ul><ul><li>ENTHALPY OF FUSION </li></ul><ul><li>IONIZATION POTENTIAL </li></ul><ul><li>SOLUBILITY </li></ul>
  13. 13. Sources of Physical Property Data and Basic Information about Chemical Substances <ul><li> </li></ul><ul><li>At the end of this lecture we will examine some of these sites to see how to find physical property data </li></ul>
  14. 14. Index to Physical, Chemical and Other Property Data - Arizona State University <ul><li>Very often we need a physical property of a substance but don't where to look for it.  This index provided by Arizona State University can be very helpful. There is a link to this from . </li></ul><ul><li>As an example, we need information on the dielectric constant for several substances.  We obviously start by clicking on &quot;D&quot;. </li></ul>
  15. 16. Thermodex <ul><li>Thermodex , an index of selected thermodynamic handbooks , was created and is maintained by the Maillet Chemistry Library of the University of Texas at Austin. It contains records for printed and web-based compilations of thermochemical and thermophysical data for chemical compounds and other substances. You can select one or more compound types and link them to one or more property terms, and ThermoDex will return a list of handbooks that might contain this data.  You must select the property and the type of property that you are seeking.  In the next slide we will do a search for handbooks that may provide the heat capacity of hydrocarbons. </li></ul>
  16. 19. Results from Thermodex <ul><li>The database found 13 items that matched the search query (the first 6 are displayed in the next slide).  This reference books are held by the Chemistry Library at the University of Texas at Austin where the database was compiled.  You must check the NJIT Library catalog to see if the source is held here.  You must check each source to see if the heat capacity of the specific hydrocarbon of interest to you is there.  It would not hurt to check several sources to see if the values match. </li></ul>
  17. 21. NIST Chemistry Webbook <ul><li>NIST , National Institute of Standards and Technology, is  a non-regulatory federal agency within the U.S. Department of  Commerce. Its mission is to develop and promote measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life.   The NIST Chemistry WebBook contains: </li></ul>
  18. 22. NIST Chemistry Webbook <ul><li>Thermochemical data for over 7000 organic and small inorganic compounds: </li></ul><ul><li>Enthalpy of formation </li></ul><ul><li>Enthalpy of combustion </li></ul><ul><li>Heat capacity </li></ul><ul><li>Entropy </li></ul><ul><li>Phase transition enthalpies and temperatures </li></ul><ul><li>Vapor pressure </li></ul><ul><li>Reaction thermochemistry data for over 8000 reactions. </li></ul><ul><li>Enthalpy of reaction </li></ul>
  19. 23. NIST CHEMISTRY WEBBOOK <ul><li>Free energy of reaction </li></ul><ul><li>IR spectra for over 16,000 compounds. </li></ul><ul><li>Mass spectra for over 15,000 compounds. </li></ul><ul><li>UV/Vis spectra for over 1600 compounds. </li></ul><ul><li>Electronic and vibrational spectra for over 4500 compounds. </li></ul><ul><li>Constants of diatomic molecules (spectroscopic data) for over 600 compounds. </li></ul><ul><li>Ion energetics data for over 16,000 compounds </li></ul><ul><li>Thermophysical property data for 74 fluids </li></ul>
  20. 24. Searching the NIST Chemistry Webbook <ul><li>Let us search for gas phase thermodynamic data on bromoform.  As you can see on the next slide, there are several search options for this database.  We will search on the name of the substance. </li></ul>
  21. 28. Materials Safety Data Sheets (MSDS) <ul><li>A Material Safety Data Sheet (MSDS) is designed to provide both workers and emergency personnel with the proper procedures for handling or working with a particular substance. MSDS's include information such as physical data </li></ul><ul><li>MSDS may be found from </li></ul>
  22. 29. Other Sources of Property Data <ul><li>Sigma-Aldrich Catalog </li></ul><ul><li>Chemicalland21 </li></ul><ul><li>Chemical </li></ul><ul><li>Chemspider </li></ul><ul><li>Knovel – NJIT has access to a small sample database, but AICHE student members have access </li></ul>
  23. 30. Summary of This Tutorial <ul><li>In the physical chemistry laboratory at NJIT you will do experiments to find physical properties of chemical substances.  These experiments were originally done years ago and reported in the literature.  You must find these values and compare them with the results of your experiments.  As you advance in your academic career and if you eventually work in an industrial laboratory you will likely need to find physical property data </li></ul>
  24. 31. Points to Remember <ul><li>Original research including the first reporting of physical properties is published in journals and conference proceedings and eventually will appear in review articles, monographs, and textbooks.  This information may be found in these sources, but much it is much easier to obtain them through print or electronic data compilations. </li></ul><ul><li>There are over 20 million unique chemical substances that have been reported in the literature.  It is much easier to find data on common substances.  The overwhelming majority of all chemical substances have been reported in the literature only once or twice.  Thus, many properties for those substances have not been documented in the literature. </li></ul><ul><li>It is quite possible to find the same property data in several sources.  The values may differ.  A good data compilation will provide a reference to the original literature where the original experiment which yielded the data is documented. </li></ul>
  25. 32. Points to Remember <ul><li>You may have to search several sources to find the desired property information.  Very often a data compilation will have information on the property of interest, but not for the compound of interest to you. </li></ul><ul><li>Material Safety Data Sheets are often a good source for  property data. </li></ul><ul><li>There are useful indexes to physical and thermochemical data from Arizona State University , University of Texas at Austin , and Vanderbilt University . </li></ul><ul><li>Bruce Slutsky, Technical Reference Librarian at NJIT, has compiled a list of electronic sources at </li></ul>