Text Readings: Chap 4

Molecule or Report of the Week: Industrial Chemical Report - mostly chlorine compounds.

Text Chapters - 8, 9, 16

 Introduction: Since prehistoric times, people have made a variety of "things" and used them for tools, weapons, shelter, transportation, food, and clothing. The "things" are derived from natural and mineral resources - the source of all chemical elements.

A modern industrial society drills and pumps, digs and mines rocks, minerals, oil, and gas from the earth; and extracts and pumps molecules and compounds from the air and water. Raw materials are refined, processed, manufactured, and synthesized into usable compounds and materials - all through the knowledge and processes of chemistry. Stop for a moment and contemplate where the nearest material that you see came from.  For this report we will concentrate primarily on compounds using salt, (NaCl) as the major resource.

This is part of the Ecological Foot Print calculated in the the Topic 1. In this topic we will look at some industrial chemicals - some of which you may not use directly, but form the basis for the synthesis of many compounds and materials used in a modern society. Some questions included: What is the source of raw materials? What is the environmental impact of obtaining the raw material? How is the chemical made from the raw materials? are there any related products? How is the product used and discarded?

Each person may choose ONE compound from those on the bottom of this question and write a brief report.  Please check the discussion forum so that you select a compound not already chosen.

First use the text book, then look at some of the general internet sites (sections 1-5 on the left). Then use various "search engines" such as Google on the internet or a Science encyclopedia to find as much as possible of the following information.

Wikipedia is an online encyclopedia which can be used to find a lot of info about specific chemicals and many other things as well.  This is a good place to start and get other references as well.
Sulfuric Acid Growth
Ammonia and nitric acid  Nitrogen: Food or Flames
Chlorine and Sodium Hydroxide Chlorine Tree - brief version
** A MUST LOOK At ** Chlorine Tree - extensive version - opens with a short video, then can click on branches for more detail.
How is Chlorine Made?
Derivatives of petrochemicalsProfONotes: Petrochemicals
ProfONotes: Polymers

Agency for Toxic Substances and Disease Registry (ATSDR) - can search on names of compounds and find facts and uses and toxicity.

Write a short report (about 5 paragraphs) to summarize your findings.  Think of the below requirements as a Life Cycle Analysis of the chemical or product.  Use the graphic and the first 4-5 pages as an example for this assignment.

1. Source of raw materials;
2. Manufacturing - Synthesis reactions (words or equations) and processes;
3. Beneficial uses of the compound and other products made with the compound;
4. Health hazards in using the compound AND Environmental impacts or hazards (in making the compound, in its use, and disposal or recycling possibilities);
5. Any other interesting details.

 Assignment: Pick ONE compound that no one else has done.

Sulfuric Acid
Ammonia
Chlorine gas- link to How is Chlorine Made?
Hydrochloric Acid-
Sodium Hydroxide  to make soaps, paper, food processing
sodium chlorite or sodium chlorate
Sodium Hypochlorite (Bleach)
ProfONotes: Polymers
Polyvinyl chloride , PVC - the poison plastic - Greenpeace
Polyamide (Nylon)
Kevlar
Teflon
Silicones - Silicon tetrachloride
Ethylenedichloride
chloroform
chlorine dioxide - a paper making substitute for chlorine
CFC
HCFC
tetrachloromethane or carbon tetrachloride
Trichloroethylene -  (TCE) facts and uses
Perchloroethylene - (PERC) facts and uses
Methylene Chloride solvent and methylene chloride
PCB - Polychlorinated Biphenyl, PCB -EPA, PCB - Toxic Alert
DDT
Heptachlor
Pentachlorophenol (PCP)
Chlordane
Dioxin HomePage
Dioxin May not be that Bad - Page from American Chemistry Council gives
a link on special cases of high exposure to Dioxin -

OR you may pick any chlorine compound from the site.  Just scan some of the compounds until you find one that looks interesting and click on it for a full report.

2. II.& III. Content Questions A and B:
   

Text Readings: Chap 4

1. Atom and Ion Electron Arrangements

 A. Bohr Diagram Review

 Text p. 85-87

ProfONotes: Positive Ions

 Notes: The Bohr model provides the initial insights about the arrangement of electrons in energy levels. The maximum number of electrons in an energy level is calculated as follows:
energy level   max no. of electrons
1                           2
2                           8
3                         18
4                         32

A Bohr Diagram is used to show the number and arrangement of electrons in various energy levels. The arrangement of all electrons in a particular atom can be determined by using the periodic table and the principle that electrons fill the lowest energy levels first.
A simple BOHR DIAGRAM can be used to represent the atoms:

For example: Li atom with atomic number 3 has 3 total electrons is: 2e-  in energy level 1 and  1 e- in energy level 2
For example: Na atom with atomic number 11 has 11 total electrons is: 2e- 8e- 1e- in energy levels 1, 2, and 3
See text for more details.

QUES. 1: Give the Bohr diagrams (just list the number of electrons for each energy level) and the Lewis Symbols for the following elements: H, C, N, O, F, Ne, Mg, Al, S, Cl. Each student should do 4 different ones and you may pick other elements with atomic numbers from 1 to 18.

 B. Electron-Dot Structures or Lewis Symbols

 Text p. 93-95

ProfONotes: Lewis Diagrams

Notes: If the previous examples are examined carefully for relationships with the periodic table, the following facts should become evident: lithium, and sodium all have one electron in the outer energy level and these elements are all in Group I.

Electron and Group Number Principle: The number of electrons in the outer energy level can be determined by finding the group number for that element.
The number of electrons in the outer energy level is the fundamental basis for the fact that elements in the same group have similar properties. The formation of ions and compounds are related to how many electrons are in the outer energy level of the atoms.

QUES. 2: Text p. 113 - Do Exercise 14 or 26 or 27 or 28. Each student pick one. Just describe the process and give the number of electron dots for the starting elements and then the ions.

QUES. 3: Text p. 114 - Do Exercise 37 or 39. Each student pick one. Just describe the process and give the number of electron dots for the starting elements and give the final formula.

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2. Ionic Compounds

 A. Types of Compounds

 ProfONotes: Types of compounds

Notes: The molecules may be divided into two groups. Those molecules that consist of charged ions with opposite charges are called IONIC. These ionic compounds are generally solids with high melting points and conduct electrical current. The other type of molecules are called COVALENT and do not consist of ions. Covalent compounds have low melting points and do not conduct electric current.

 B. Formation of Ions

 Text p. 95-97

ProfONotes: Positive Ions

ProfONotes: Negative Ions

Notes: The IONS have properties that are completely different from those of their individual element atoms. Whereas elements are neutral in charge, IONS have either a positive or negative charge depending upon whether there is an excess of protons (positive ion) or excess of electrons (negative ion).

 C. Octet Rule

 Text p. 95

Notes: Octet Rule: Elemental atoms generally lose, gain, or share electrons with other atoms in order to achieve the same electron structure as the nearest rare gas with eight electrons in the outer level.

 Text p. 95-99

ProfONotes: Ionic Compounds

 Notes: The Octet Rule is the basis for the predictions about the charges on ions. Ionic compounds are formed as the result of the formation of positive and negative ions. Electrons are actually transferred from one atom to another to form rare gas electron structures for each ion. The atom which forms a positive ion loses electrons to the atom which gains electrons to form a negative ion. A compound is not stable unless the number of electrons which are lost and gained are equal.

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3. Covalent Compounds

 A. Simple Diatomic Molecules

Text p. 100

ProfONotes: Types of compounds

  Notes: Covalent compounds share two electrons in forming a bond between atoms. Covalent compounds are formed only by the interactions of non-metal atoms. The number of atoms which make up covalent molecules is determined by the number of electrons in outer levels and the Octet Rule.

The simplest covalent molecule is the diatomic hydrogen molecule. The Lewis Symbols are: H . and H . ; The "octet" for hydrogen is only 2 electrons since the nearest rare gas is He. The diatomic molecule is formed because individual hydrogen atoms containing only a single electron are unstable. Since both atoms are identical a complete transfer of electrons as in ionic bonding is impossible -- How would you determine which atom should lose an electron and which atom should gain an electron? Instead the two hydrogen atoms share both electrons. Other examples are fluorine, chlorine, bromine.

Text p. 101-102

ProfONotes: Lewis Diagrams

 Notes: Compounds which need more than one electron to complete the octet will share as many electrons as necessary in order to complete the octet. This translates into forming two or more bonds to atoms. The water molecule is a good example of this. The Lewis Symbols are:

H (1 electron) and O (6 electrons) = H2O

Hydrogen needs only l electron while oxygen needs 2 electrons to complete the octet. Since hydrogen can only share one electron, two hydrogen atoms with one electron each will be needed by oxygen to complete the octet.

C. Multiple Bonds

 Text p. 103

Notes: Atoms may share more than 2 electrons. Diatomic oxygen shares 4 electrons and diatomic nitrogen shares 6 electrons.

Example: Determine the formula for an oxygen molecule.

Solution:

Lewis Symbols: O (6 electrons) + O (6 electrons)

Two electrons in each oxygen are needed for an octet, therefore, they need to share a total of 4 electrons between them. This makes two sets of two electrons or two bonds or a double bond.  

QUES. 4: Describe the electrons in bonding for any TWO of the following molecules: sodium chloride, magnesium chloride, potassium oxide chlorine, ammonia, nitrogen, carbon tetrachloride, methane, carbon dioxide, ethylene, and hydrogen chloride.

Just describe what you are doing like how many electrons and where they are located.

Answers are found somewhere in text chap 4.

Text p . 96-105

4. Shapes of Molecules

Molecular Shapes

ProfONotes: Molecular Geometry

QUES. 5:  Read carefully the rules for determining the shapes of the molecules. Do a or b or c. Second and third student does the ones not already done.

a. Explain the difference between H2O and CO2 (both molecules have one central atom with two others attached). Use the ideas of bonding and non-bonding pairs of electrons.

b. Explain the difference between H2O and O3 (both molecules have one central atom with two others attached). Use the ideas of bonding and non-bonding pairs of electrons.

100. c.Explain the difference between BH3 and NH3 (both molecules have one central atom with three others attached. Use the ideas of bonding and non-bonding pairs of

     

     electrons.
     
      ProfONotes: Molecular Geometry
     

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Non-polar bond = equal electron pair sharing; recognize by two identical atoms and carbon-hydrogen is a very common exception.

p. 100-101

ProfONotes: Non-Polar Bonds

 p. 103-104, 106-107

ProfONotes: Polar Bonds

QUES. 6: Classify the following covalent bonds as polar or non-polar: H-H, H-Cl, H-O, H-C, H-N, O-O, N-N, Cl-Cl.

If the molecule is polar, describe which atom has a partial positive and negative charge.

Each student should pick 2 or 3 that have not been done.

In addition, explain how carbon dioxide can have polar bonds, but be a non-polar molecule.

p. 100-107
ProfONotes: Non-Polar Bonds
ProfONotes: Polar Bonds

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6. Compounds - Changes of State

Properties of Solids, Liquids, and Gases

 Text p. 4-7

ProfONotes: Physicial Properties

 Changes of State: Solid to liquid, liquid to gas

Do a or b.
QUES. 7a: At the molecular level, contrast and explain how the molecules behave or move in the solid, liquid, and gas state.
or
QUES. 7b: At the molecular level, contrast and explain what happens to the molecules when a solid melts OR when a liquid boils or vaporizes. Include statements relating to temperature and energy.
Text p. 4-7

7. Changes of State - Intermolecular Forces

Use for all of the following: ProfONotes: Intermolecular Forces

Ionic Forces - full positive and negative charges in ionic crystals - strongest of all forces. Positive and Negative charges attract. Example: Salt - melts at 800 C.

Text p. 107, 110

Text p. 107, 110

 Text p. 107, 110

ProfONotes: Hydrogen Bonding

 Text p. 107, 110

QUES. 8: Compare, describe, and contrast any of the pairs below:

a. ionic vs. dipole forces
b. dipole vs. hydrogen bonds
c. dipole vs. dispersion forces

Each student pick one above.

 Text p. 107, 110

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Solutions: A solute is dissolved into a solvent to make a homegeneous solution.

 p. 177- 178

ProfONotes: Solubility

ProfONotes: Solubility of Salts

Ionic and polar substance dissolve in polar water. Examples: salt in water, alcohol in water.

Non-polar substances do not dissolve in water. Example: oil does not dissolve in water.

Non-polar substances dissolve in non-polar solvents. Example: oil dissolves in gasoline

 

QUES. 9: Explain at the molecular level how salt dissolves in water. 

Text p. p. 177- 178

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4. IV. Issue Question:  Should the Use of Chlorine for the manufacture of chlorine containing compounds be banned?
   
   

Option # 1: Complete ban on use of all chlorine containing compounds.

Option # 2: Limited ban only on potentially harmful classes of compounds.
For example ban all organochlorine pesticides or ban all chlorine containing plastics.

Option # 3: No ban, or extremely limited ban on compounds proven to cause harm.
For example ban only those chlorine containing compounds which have been proven to harm the environment or toxic to humans and animals i.e. DDT, PCB's

For this issue debate, you may self select the position that you would like to promote.

INTRODUCTION:

Chlorine in the elemental state is is pale green poisonous gas. In various other forms it is present in the ocean water, in common table salt, highway salt to melt ice, in bleach, and as a disinfectant in drinking water. Chloride ions or chlorine as the element is used in the manufacture of a wide variety of industrial compounds including 85 percent of all pharmaceuticals, 96 percent of all agricultural pesticides and herbicides, and a wide range of plastic type materials including PVC pipe. It is also used in the bleaching of wood pulp to make paper.

A group of chemicals called organochlorines-substances that contain chlorine and carbon that is at the heart of the chlorine controversy. They include polychlorinated biphenyls (PCBs), dioxins, the now-banned pesticide DDT and others that are tough to destroy and are known or believed to be highly toxic. Over the years, they have been released into the environment through such sources as industrial effluents and smokestack emissions, discharges that in many cases are now reduced or banned. The organochlorine compounds are not readily degraded in the environment and persist many years. In the Great Lakes region, PCBs and other chlorinated compounds have been found in very small amounts. However through a process of bio-magnification, the organochlorine compounds concentrate in the fats of fish as they move up the food chain. The result is that the Great Lakes states issue advisories on the size and quantity of lake fish that are safe to eat. And yet scientific evidence that PCBs, for instance, cause human cancer or impair development in infancy and childhood has yet to be proven conclusive. There is a high degree of concern for the health effects of a organochlorine compound called dioxin. Dioxin is produced from a variety of sources involving the combustion or incineration of a wide variety of materials. Much research has tried to establish the health effects of this compound including birth defects, cancer, and endocrine disrupters,

International Joint Commission, a quasi-governmental board that oversees cleanup efforts on the Great Lakes recently reiterated its two-year-old call for phasing out the use of chlorine and chlorine-containing compounds. That followed a call by the Clinton administration for a 30 month study of chlorine's uses and potential health effects that could lead to a plan to "substitute, reduce or prohibit the use of chlorine and chlorinated compounds."

The chemical industry vigorously, even vehemently disagrees with that analysis. About half of all commercial chemistry involves chlorine, worth an estimated $70 billion annually in sales. So phasing out chlorine would be not only costly and uncertain, in the industry's view, but also not necessary.  "Science does not justify this wholesale ban or phase-out of chlorine," said Jeffrey Van, spokesman for the Chemical Manufacturers Association, the industry's Washington-based trade group. "Not all environmental risks are alike. Some are larger than others. Some, indeed, are mythical."

In this century, as the number and type of chemicals used by industry have exploded, chlorine has become an increasingly integral part of the business because it is a highly reactive element that readily combines with a wide range of other elements.
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RESEARCH LINKS:
Background information:

1. Chlorine Tree - brief version
   

2. Chlorine Tree - extensive version - opens with a short video, then can click on branches for more detail.
   

3. Discover Chlorine Universe -
   

4. Chlorine Council - Many links and good information
   contains The Chlorine Story - four pages
   Chlorine Everyday Uses -
   
   

5. Silent Spring -Revisited
   

6. Toxic Alert - many links to chlorinated compounds
   

More Specific Sites:

1. PVC - the poison plastic - Greenpeace
   PVC Case Study - Chemical Hertiage
   What is Dioxin?
   Dioxin HomePage
   

2. Dioxin May not be that Bad - Page from American Chemistry Council gives a link on special cases of high exposure to Dioxin -
   

3. DDT
   

4. A Chlorinated Compound in Toothpaste
   

5. List of contaiments in Drinking and Ground Water - Look for those that contain chlorine such as disinfection by products and then view a fact sheet on the specific chemical.
   
   

PAPER MAKING - WITH AND WITHOUT THE USE OF CHLORINE

Chlorine in making paper - Greenpeace

1. Chlorine in Making Paper
   

2. Fact Sheets on using Chlorine Dioxide.
   
   

HEALTH EFFECTS:

1. Health and Safety - links - Chlorine Council
   

2. Dioxin HomePage
   

3. What are POPs? -Persistant Organic Pollutants - Click on POPs Greenpeace  POPs in the Arctic -
   

4. The Poisoned North -
   

5. Cl Drinking Water Disinfection.
   Paper on the use and history of using chlorine in water treatment.
   

6. Chlorine and water Disinfection - Chlorine Council
   

7. Chlorination of water and side effects
   

8. Nowhere to hide - Pesticides
   

9. Biomagnification of DDT
   

10. Case Study - Malaria and DDT
    
    

Sites and Papers which more or less support the YES BAN:

1. Canadian Chlorine Coordinating Council. - Advocates a limited chlorine phase out. Check out the references in the section Science and methods that industry has used to reduce chlorine in the section Case Studies.
   

2. PVC - the poison plastic - Greenpeace
   

3. Why PVC is bad News -
   

4. PVC Alternatives Database - Greenpeace
   

5. Building a PVC free Future - Greenpeace
   

6. Why Chlorine Must be Phased Out - Greenpeace
   

Sites and Papers which more or less support the NO BAN:

1. Chlorophiles: A web site maintained by workers in the PVC Industry. - Many explanatory papers and articles that rebut Greenpeace articles. Many links and articles on chlorine.
   

2. Chlorine in the World  - Natural sources of chlorine as well as chlorine use for industrial synthesis.
   

3. Chlorine Chemistry Division - Gives more of the positives on chlorine
   

4. Chlorine Risk - A rebuttal of a Greenpeace brochure claiming that 52 people die each day from chlorine related factors.
   

5. CEI: RACHEL'S FOLLY--The End of Chlorine - Rebuttal of Greenpeace's position to Ban all chlorine compounds.
   

ISSUE QUESTION REPORT:
Should the Use of chlorine for the manufacture of chlorine containing compounds be banned?

The report should be 4-6 paragraphs and include the following:

1.  (Worth two paragraphs) Discuss two industrial or household chorine containing chemicals and their uses. Compounds that may be considered here include:  PVC, DDT, PCB, dioxin, POPs, organo-pesticides and others from Part I - Molecules of the week. OR you may pick any chlorine compound from the site.  Just scan some of the compounds until you find one that looks interesting and click on it for a full report.

What is the technology that is being helped by this chemical? What is the beneficial use of the compound? What is the side effect environmental problem caused by the compound?  What adverse health effects for humans and other organisms are caused by it, if any.

2.  Include ONE of the following (a-f) in your discussion:

a.  What kinds of chemicals are used in the making of paper? Are there chlorine substitutes available? Is the paper making process a very friendly process to the environment even though is uses a natural renewable resource?

b. Is it possible to ban chlorine since it is a natural chemical? Are some "bad" organochlorine compounds already made in nature such as dioxin, if so list some and explain how they are formed?

c. Explain the issues in a proposed final worldwide ban of DDT - an organochlorine pesticide -may include other organochlorine pesticides (such as aldrin, dieldrin, arochlor, chlordane). Is there still a beneficial use of DDT?  Case Study - Malaria and DDT
 

d.  How hard is it to correlate specific health problems which may or may not be caused by specific chemicals such as some of the organochlorine compounds?  Choose a specific compound to try to answer this question.  Text p. 550-555 and also try Agency for Toxic Substances and Disease Registry (ATSDR) - can search on names of compounds and find facts and uses and toxicity.

e. Why is chlorine used in water treatment?  Are their substitutes?  What is the benefit and also the health risk? Are you more likely to get sick or die if chlorine is not used in drinking water? (Since everyone usually wants to do this question it is limited to the first 4-5 students)

f.  Is it right or ethical to continue making chlorine chemicals - mostly organopesticides (already known to cause adverse health effects? ...especially those compounds banned in the U. S. but exported to other countries?  Some of these banned include: In addition to DDT, the United States has banned aldrin, dieldrin, arochlor, chlordane, heptachlor, mirex hexachlorobenzene, oxychlordane, toxaphene and others.

However, several organochlorines are still registered for use, including lindane, endosulfan, methoxychlor, dicofol and pentachlorophenol.

3.  Final summation of the main issue question.
Should the Use of chlorine for the manufacture of chlorine containing compounds be banned?  Please pick and support one of the options below.

Should all uses of chlorine be banned when only a few chemicals cause problems?  Why should these compounds be banned or not banned? Do the negatives out weigh the positives on continued use of the chlorine compounds?

Option # 1: Complete ban on use of all chlorine containing compounds.

Option # 2: Limited ban only on potentially harmful classes of compounds.
For example ban all organochlorine pesticides or ban all chlorine containing plastics.

Option # 3: No ban, or extremely limited ban on compounds proven to cause harm.
For example ban only those chlorine containing compounds which have been proven to harm the environment or toxic to humans and animals i.e. DDT, PCB's.

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5. V.  Response or Ask a Question - respond or comment to someone else, or use General Questions to ask a general question that the Prof or others might answer.  Extra responses earn extra credit (1 pt/ques. up to 2 points)
   
   Response Format:  What or why is something interesting?  Then add a new perspective or viewpoint.  Needs to be longer than one sentence.
   
   Ask a question Format:  Give a little background of what you already know or what is your interest, then add what you already know, then finally ask your question.
   

Content Question A

Ques. No.      Student ID #

Ques. 1       2, 20, 30

Ques. 2       6, 14, 24         

Ques. 3       10, 18, 28

Ques. 4       1, 19, 29

Ques. 5       3, 7, 8, 15, 25,

Ques. 6       9, 11, 17, 27

Ques. 7       5, 13, 23, 16

Ques. 8       8, 16, 27, 26

Ques. 9       4, 12, 21, 22

Charles E. Ophardt, Professor of Chemistry, Elmhurst College, Elmhurst, IL 60126, charleso at elmhurst.edu, Copyright 2009