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Welcome to CHE 102Introduction to Organic Chemistry

TTh, 6-9:30 pm

Instructor: Abdi Mohamed

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Lecture 1 Outline

Introduction About me Course Organization, Policies, Procedures, etc. Group Formation, Group Activity Overview

Review of Octet Rule, Molecular Shapes and Polarity Introduction to organic chemistry Alkanes

Properties of Alkanes Naming and Writing Alkane Formulas

Alkanes with Substituents Functional Groups

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Course Organizationhttp://facweb.northseattle.edu/amohamed/CHE102.htm

• Class meeting days and times– Lectures: Tues 6-9:15 pm and on Thu 6-7:15 pm in AS1614– Labs: Thu 7:15 to 9:15 pm in AS1519

• Course prerequisites (page 1 of syllabus)• Modes of instruction: hybrid of traditional lecturing and active

learning: Class structured so that you can teach and learn from others

– Lecture sessions: pointers and guidance– Active learning: group activity, active learning exercises, etc

• Means of assessment: holistic approach (syllabus)– Group activity, quizzes, lab work, HW, 2 group presentations…..…total of 44%

– 4 exams: 3 midterms (lowest dropped) and a final …….....total 56%

MUST GET 40% of EXAM POINTS TO PASS CLASS (140/400)

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Intended Outcomes of Group Activities

Enhance your learning and retention of concepts learned via peer-to-peer teaching and helping others

Help catch and reduce the number of mistakes and misconceptions people tend to make when working on their own

Identify difficulties within groups and then bring to the full class for discussion and clarification

Facilitate the development of good study habits Develop your skills working with others in a group Foster the development of responsibility for the learning of

others as well as your own

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Reflections of CHE 101 Students on Group Activities and Active Learning Exercises

0%15%30%45%60%75%90%

105%120%

helfpul hindrance

% S

tude

nts

Number Percent

Helpful (some suggested improvements) 48 91%

Hindrance 5 9%

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Reflections of CHE 101 Students on Group Activities and Active Learning Exercises

Comments of those who found group activities helpful …“Looking at a problem from point of view of a classmate can help you figure out the problem”

“Other students in the class were able to clarify subjects that I didn’t understand at first”

“You could learn a lot from helping to teach others and from working through confusing things with help from others”

“It helped to bounce ideas off others. It helped to see that others had the same problems as me. Sometimes we could work together to solve a problem”

“It made me actually work with what I had just learned instead of listening and not really paying that good of attention. They really helped me but I think you should make a copy for everyone”

“I learned this way the best”

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Reflections of CHE 101 Students on Group Activities and Active Learning Exercises

Comments of those who found group activities hindrance

“Sometimes people move faster than I do, hard to keep up and understand”

“I tend to learn the best when I have time to review a concept on my own”

“I would have liked to learn my own work and study from that”

“Generic comment: I can’t focus on the problems … some students were not focused”

“Sometime we didn’t go as fast as I wanted and sometimes we got distracted”

“My group members often took it upon themselves to get it done, not caring if they skipped what they didn’t understand and if the members of their group understood”

“Everyone have different primary knowledge, so it was little bit hard (and English problem for me)”

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Reflections of CHE 101 Students on Group Activities and Active Learning Exercises

Comments of those who had suggestions for improvement“ (Helpful) if you didn’t know how to solve a problem, someone in the group would and could teach you how to solve it. (Issue) sometimes talking about non-chemistry related problems would set me off track. ”

“(Helpful) Teaching is the best way of learning. (Issue) if I didn’t understand the material I felt bad for holding others in my group back”

“(Helpful) I could bounce ideas off someone else and confirm procedures. (Issue) I I often understood the material and became impatient with those who did not. But I got better at it as the quarter progressed”

“(Helpful) You could learn from others. (Issue) People moved quickly and would not slow down to answer questions. Some people did not contribute anything!”

“(Helpful) My weaknesses-a particular kind of problem or not noticing certain details were often others’ strengths really. (Issue) if I hadn’t already gotten familiar with a concept, group work just confused or frustrated me because everyone was at a different place”

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Learning from the Past: New Goals for GA

Each group assigns “recorder” At the beginning of activity, recorder asks individuals how much

of the concept of that activity each one understands Recorder notes each member’s participation Recorder asks at the end every member if they understood the

concept and if not, other members must explain the problem At the end of activity, recorder responds to questions asked by the

instructor about the group activity and participation Each activity is worth 10 points. For individual students

Points will be deducted for lack of participation (noted by the recorder and instructor)

Points deducted for non-chemistry related discussion for lengthy period

Observations made by the instructor would count towards the subjective 20 point “Student Evaluation” given at the end (3%)

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First Essential Group Activity

Say hello and introduce yourselves Discuss why each of you is taking the class. Select a “recorder” by finding the person in your group

whose birthday is closest to today’s date Record the following on a sheet of paper

o Your group number at the top of a sheet of paper

o 1st and last names of all group members

o Interest of the group members

Adopted from Ken Marr, Chemistry/Biology Instructor, GRCC

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Introduction to Organic Chemistry

Think about the structure shown below and then answer the following two questions?

What is organic chemistry? Think about the trends you see: what is common among all of the structures shown?

Why is it essential to study organic chemistry? Why CHE 102?

C3H8 C C

H

H

H

H

H

H

Propane Ethane Tylenol

Pentyl Acetate (bananas) Aspirin

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Organic Chemistry is Essential

Health Sciences Physicians Nurses Dentists Nurse Anesthetist Nutritionist Etc

Scientists Pharmaceuticals (chemistry of drugs) Household Products (Dichloromethane in dry

cleaners,plastics, etc) Essential for understanding biology and biochemistry

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CHE 101 ReviewIonic and Covalent Bond: The Octet Rule

Recall the “Octet Rule.” What is the octet rule? Atoms adjust their valence electrons to achieve noble gas

electron configuration …a key to understanding the ways in which atoms bond and form compounds

What determines whether a bond is ionic or covalent? In ionic bond, electron octets are formed by transfer of

electrons

NaCl, MgO In covalent bond, electron octets are formed by sharing

electrons

HCl, H2O, Br2

Periodic table indicates valence electrons

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How many bonds can elements that tend to form covalent bonds have?

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Predicting Molecular Polarity: An activity

Which of the following is polar and which one is nonpolar?

HBr, Br2, H2O, H2S, CH3Cl, CCl4, CH2Cl2?

Polar:

NonPolar:

What predictors have you used to decide the molecular polarity of the above molecules?

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Predicting Molecular Polarity

Representing Molecular Polarity

H Cl

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I s HCl a polar Molecule? What about N2?

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Electron Density Picture

H-Cl

Representing Molecular Polarity

H-Cl N2

Asymmetrical Symmetrical

Charge Distribution: Symmetrical or Asymmetrical?

Figures from the website of Dr. K Owens, CHE 150, NSCC

Molecular polarity in covalent bonds is primarily based on shape:

Symmetrical molecules are nonpolar

Nonsymmetrical molecules are polar if there is at least one lone pair on central atom or there is at least one polar bond

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Predicting Molecular Shapes

TABLE 4.16 Examples of Shapes of Molecules

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Predicting Molecular Shapes

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Pause: Active Learning Exercise 1

Do Problems 1-5 of ALE1 With this activity, work with your group

members. In the future ALE will be done individually, with answers checked with group members after wards

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Summary: Organic Compounds

An organic compound Is a compound made from carbon atoms. Has one or more C atoms. Has many H atoms. May also contain O, S, N, and halogens.

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Properties of Organic CompoundsTypical organic compounds Contain carbon. Have covalent bonds. Have low melting points. Have low boiling points. Are flammable. Are soluble in nonpolar

solvents. Are not soluble in water.

Oil (organic) and

water (inorganic)Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

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Learning Check

Identify each characteristic as most typical of

compounds that are (I) inorganic or (O) organic.

1. Has a high melting point

2. Is not soluble in water

3. Has a formula CH3─CH2─CH3

4. Has a formula MgCl25. Burns easily in air

6. Has covalent bonds

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Section 11.5 Functional Groups

Functional groups determine the reactivity of organic molecules, thus organic molecules are classified by their functional groups

We will study each functional group in detail in the remaining of the quarter

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Functional Groups That We will Study

Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

TABLE 11.9

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Names of Alkanes

The names of alkanes Are determined by the IUPAC (International

Union of Pure and Applied Chemistry) system. Use a prefix to indicate the number of carbons

in a chain. End in –ane.

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IUPAC Names for Alkanes

Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

TABLE 11.2

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Learning Check

A. Give the name of each compound:

1) CH3—CH3

2) CH3—CH2—CH3

3) CH3—CH2—CH2—CH2—CH2—CH3

B. Write the condensed structural formula of

pentane.

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Structural Formulas

Alkanes are written with structural formulas that are Expanded to show each bond. Condensed to show each carbon atom and its attached

hydrogen atoms.

Expanded Condensed

H

H C H CH4 , methane

H

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Line-Bond Formulas

Because each C atom has a tetrahedral arrangement, the order of atoms is not a straight line, but a zigzag pattern.

A line-bond formula abbreviates the carbon atoms and shows only the zigzag pattern of bonds from carbon atom to carbon atom.

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Learning Check

A. Write the condensed formula for:

H H H H H

H C C C C C H

H H H H H

B. What is its molecular formula?

C. What is its name?

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Learning Check

Write the condensed structural formula for

A. ethane

B. heptane

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Cycloalkanes

Cycloalkanes Are cyclic alkanes. Have 2H fewer than the open chain. Are named by using the prefix cyclo- before

the name of the alkane chain with the same number of carbon atoms.

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Cycloalkanes

The structural formulas of cycloalkanes are usually

represented by geometric figures,

Cyclopropane CH2

CH2 CH2

CyclobutaneCH2

CH2

CH2 CH2

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Learning Check

Name the following:

A. CH3─CH2─CH2─CH3

B.

C. CH3─CH2─CH2─CH2─CH2─CH2─CH2─CH3

D.

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Constitutional Isomers

Isomers are compounds with the same molecular formula, but a different arrangement of atoms

There are many types of isomers One type, constitutional isomers, have the same formula,

but atoms are connected in a different order

Examples:

C4H10 has two constitutional isomers:

CH3-CH2-CH2-CH3 and CH3-CH(CH3)-CH3

C2H6O also has two constitutional isomers:

CH3-CH2-OH and CH3-O-CH3

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Naming Alkanes With Substituents

In the IUPAC system,

A carbon branch is named as an alkyl group.

Halogen atoms are named as halo.

TABLE 11.5

Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings

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Guide to Naming Alkanes

Give the name of CH3 CH3

CH3─CH─CH─CH3

STEP 1 Longest chain is butane.

STEP 2 Number chain. CH3 CH3

CH3─CH─CH─CH3

1 2 3 4STEP 3 Locate substituents and name.

2,3-dimethylbutane

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Pause

Do active Learning ALE 1, # 7 -13