Webercise Sampler

MTBE  -  Methyl-t-Butyl Ether

     This short Chemistry Webercise is an example of a new educational product recently made available by John Wiley and Sons, Inc. Use of these Webercises should provide students the experience and insight needed to quickly search (or navigate the web) for a chemistry related topic and to achieve internet literacy. The Webercises have also been designed to provide users with a search for answers to important and stimulating questions about contemporary chemistry topics.

     Three Chemistry Webercises have been custom designed for students in three different types of courses. Because of many common goals in the three types of course, there is some overlap in the three sets of Webercises.

Chemistry Webercises i - For students in introductory chemistry and chemistry and society courses.
Chemistry Webercises g - For students in preparative and general chemistry courses.
Chemistry Webercises o - For students in organic chemistry courses.

     This particular Webercise on MTBE was designed as a project for a PACT course offered at the Center for Chemical Education, Miami University, Middletown, Ohio, during the summer of 1996. It has been modified considerably since it was first designed. The principal change is that it is now keyed to a Wiley Chemistry Webercises Directory internet site that has been designed specifically for use with the Chemistry Webercises. Currently this is the only Webercise that is available on the internet. The others are available in hardcopy.

     A.  Top 50 Chemicals and Chemical Production. Load the Wiley Chemistry Webercises Directory site using your internet browser by typing in the URL below in the location box or by clicking on the link directly below. Because one of the purposes of the Webercises is to have you use the Chemistry Webercises Directory, of the many URL's given here, this is the only one that is an active link.

http://murov.info/webercises.htm       Wiley Chemistry Webercises Directory site

As this site will be used often, it will save time if you insert a Bookmark for this site. Under Applied Chemistry, click on the site listed as Chemical Production, Top 50 Chemicals to access the URL site (IV-D-1):

Use the information at this site to answer questions 2 - 6 in Part A of the Questions and Solutions section (For question 1, refer to an organic chemistry text or wait as the structure will appear on one of the sites you will use to answer questions in Part C). Another site of interest for applied chemistry information at the bottom of the Properties of Substances heading is the Chemistry and Industry magazine online (II-B-6-c):

Now click Back until you return to the Chemistry Webercises Directory.

     B.  History of Chemical Engineering & Chemical Technology. Under Applied Chemistry and Oil scroll down to and click on Case Study: Petroleum - Modern Refining (IV-C-2) to reach the URL:

Use the text to answer questions 1 and 2 in Part B of the Questions and Solutions section. Now click Back until you return to the Applied Chemistry section of the Chemistry Webercises Directory. Click on Sulfuric Acid Production, The Gage of Industry (IV-B) to reach the URL:

Use the information available to answer question 3 in Part B of the Questions and Solutions section. Now again click Back until you return to the Applied Chemistry section of the Chemistry Webercises Directory. Under Oil, click on Oil: Energy or Petrochemicals (IV-C-1) to reach the URL:

Use the information available to answer questions 4 - 8 in Part B of the Questions and Solutions section.

Again, return to the Chemistry Webercises Directory.
 

     C.  Properties and Toxicity of Chemicals. Chemists quite often need to perform literature searches to find properties of substances. Properties are needed to help identify substances and to select substances for specific applications. There are many references that contain compilations of the properties of substances such as the Handbook of Chemistry and Physics or the Aldrich Chemical Catalog but sometimes these sources are not available when needed. The internet is another option for a search for properties and it is important to have some idea of what information is available and how to access it. Some of the sources that are useful are chemical catalogs, MSDS (material safety data sheets) compilations or an excellent search tool called ChemFinder Web Server. The ChemFinder Web Server has been designed to search for chemicals by name, formula and other means and provides links to MSDS and additional information sources.

The link to ChemFinder Web Server in the Chemical Webercises Directory is under Properties of Substances and Compounds. Its URL (II-B-1) is (a Bookmark here will probably be useful):

At this site, enter "MTBE" in the search position and click on "submit". It is recommended that you click on several of the entries that provide "Information about this particular compound" and browse through the material. Eventually, under MedAccess Chemical Summaries, click on the "Information about this particular compound" line. By clicking under the appropriate headings in the TABLE OF CONTENTS, you should be able to find the answers to the questions in Part C of the Questions and Solutions section.
 

     D.  Now click Back until you return to the Chemical Webercises Directory [or return to the home page of your browser (e.g., Netscape Navigator) and click on the Search option]. Use one or preferably several of the search engines (see section IX) to perform a search for information on the use of MTBE in gasoline including the reasons for its use and possible problems associated with its use. Write at least a page critically evaluating the use of MTBE in gasoline giving appropriate internet references. For appropriate citation formatting see the Chemical Webercises Directory section IX-E.

A few sites that contain information on MTBE that are listed in section VII-E of the Chemical Webercises Directory are:

http://www.tsrtp.ucdavis.edu/mtberpt
http://www.ofa.net/ofacec.htm
http://anonymous.chevron.com/chevron_root/prodserv/bulletin/phase2rfg/index.html
Octane ratings - http://www.cs.uu.nl/wais/html/na-dir/autos/gasoline-faq/part3.html

 

   

CHEMICAL PRODUCTION AND USES - QUESTIONS AND SOLUTIONS

A.  Top 50 Chemicals and Chemical Production

     1.  Draw a Lewis structure of MTBE.
 
 

     2.  What was the production of MTBE in 1995?                                          _____________

     3.  What was the production of MTBE in 1994?                                           _____________

     4.  What was the production of MTBE in 1985 (see later table at this site)?      _____________

     5.  What was the percentage increase in MTBE production between 1985 and
          1995?                                                                                                       _____________

     6.  To attempt to grasp the magnitude of the production numbers of the top 50 chemicals,
          assume the density of MTBE is 0.74 g/mL and calculate the volume in cubic meters
          (1000 Liters) of the MTBE production in 1995.

                                                                                                                        _____________

B.  History of Chemical Engineering & Chemical Technology

     1.  According to the article, what are the "five pillars of refining"?

          __________     __________     __________     __________     __________

     2.  Which of the above "pillars" sometimes requires sulfuric acid and what
           is its function?                                                                                          ____________
 
 
 

     3.  (Be sure to develop Figure 1-1) What is meant in the article by the statement "sulfuric acid
          production closely mirrors historical events"?
 
 

     4.  In 1992, what was the world consumption of oil?                                    _____________

     5.  In 1992, what was the U.S. consumption of oil?                                       _____________

     6.  In 1992, what percentage of world oil was consumed in the U.S. ?          _____________

     7.  What percent of the world's population lives in the United States?           _____________

     8.  Many parts of the world are attempting to achieve the standard of living that exists in the
          United States. What impact could this have on the world's petroleum reserves?
 
 

C.  MTBE

     1.  Fill in the physical data requested:                              melting point      _____________

                                                                                            boiling point         _____________

                                                                                            density                  _____________

                                                                                            water solubility     _____________
 
 

     2.  According to the information, how many billion pounds of MTBE were
          produced in the United States in 1992?                                                        _____________

     3.  What were the total annual industrial emissions of MTBE in 1992?            _____________

     4.  What percentage of MTBE production ends up as emissions?                     _____________

     5.  Assuming the percentage has stayed constant, use the number in A-2 above
          to calculate the 1995 emissions of MTBE.                                                   _____________ 

     6.  What are the oral LD50 (the number of g per kg of body weight that will kill
           half of the rodents given the dose) values for rodents of MTBE?                 _____________
 

     7.  To give some relevance to the LD50 values above, find the values for some more familiar
          compounds such as sodium chloride, sodium cyanide, aspirin, nicotine and vitamin C
          (use ChemFinder and/or MSDS compilations to find this information).

                                                                               compound                              LD50 (g/kg)

                                                                               sodium chloride                     _____________

                                                                               sodium cyanide                     _____________

                                                                               aspirin                                   _____________

                                                                               nicotine                                 _____________

                                                                               vitamin C                              _____________
 

     8.  Is there any evidence of carcinogenicity of MTBE in humans or animals? Explain your
          answer.
 
 

     9.  Describe and discuss any other information available about MTBE that you consider relevant.
 
 
 
 
 
 
 
 
 
 
 

D.  MTBE: A White Paper on Its Use in Gasoline (For your assistance in understanding
      why MTBE is used in gasoline, a table of octane ratings has been included below

        compound            octane rating                compound                    octane rating

        n-octane                -19                                2,2,4-trimethylpentane     100
        n-heptane                 0                                   ethanol                           105
        n-hexane                24.8                               methanol                         105
        n-pentane               61.7                               benzene (tech. grade)     106
        cyclohexane           83.0                              MTBE                             115
        n-butane                 93.8                              p-xylene                          116.4
        propane                 97.1                              toluene                             120.1
 
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