1 Welcome to CHE 102 Introduction to Organic Chemistry TTh, 6-9:30 pm Instructor: Abdi Mohamed

2 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

3 Course Organization 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)

4 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

5 Reflections of CHE 101 Students on Group Activities and Active Learning Exercises NumberPercent Helpful (some suggested improvements)4891% Hindrance59%

6 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”

7 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)”

8 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”

9 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%)

10 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 oYour group number at the top of a sheet of paper o1 st and last names of all group members oInterest of the group members Adopted from Ken Marr, Chemistry/Biology Instructor, GRCC

11 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? C3H8C3H8 Propane Ethane Tylenol Pentyl Acetate (bananas) Aspirin

12 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

13 CHE 101 Review Ionic 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, H 2 O, Br 2 Periodic table indicates valence electrons

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

15 Predicting Molecular Polarity: An activity Which of the following is polar and which one is nonpolar? HBr, Br 2, H 2 O, H 2 S, CH 3 Cl, CCl 4, CH 2 Cl 2 ? Polar: NonPolar: What predictors have you used to decide the molecular polarity of the above molecules?

16 Predicting Molecular Polarity 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

17 Predicting Molecular Shapes TABLE 4.16 Examples of Shapes of Molecules

18 Predicting Molecular Shapes

19 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

20 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.

21 Properties of Organic Compounds Typical 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

22 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 CH 3 ─CH 2 ─CH 3 4. Has a formula MgCl 2 5. Burns easily in air 6. Has covalent bonds

23 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

24 Functional Groups That We will Study Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings TABLE 11.9

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26 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.

27 IUPAC Names for Alkanes Copyright © 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings TABLE 11.2

28 Learning Check A. Give the name of each compound: 1) CH 3 —CH 3 2) CH 3 —CH 2 —CH 3 3) CH 3 —CH 2 —CH 2 —CH 2 —CH 2 —CH 3 B. Write the condensed structural formula of pentane.

29 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 HCH 4, methane H

30 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.

31 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?

32 Learning Check Write the condensed structural formula for A. ethane B. heptane

33 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.

34 Cycloalkanes The structural formulas of cycloalkanes are usually represented by geometric figures, Cyclopropane CH 2 CH 2 CH 2 Cyclobutane CH 2 CH 2 CH 2

35 Learning Check Name the following: A. CH 3 ─CH 2 ─CH 2 ─CH 3 B. C. CH 3 ─CH 2 ─CH 2 ─CH 2 ─CH 2 ─CH 2 ─CH 2 ─CH 3 D.

36 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: C 4 H 10 has two constitutional isomers: CH 3 -CH 2 -CH 2 -CH 3 andCH 3 -CH(CH 3 )-CH 3 C 2 H 6 O also has two constitutional isomers: CH 3 -CH 2 -OH and CH 3 -O-CH 3

37 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

38 Guide to Naming Alkanes Give the name of CH 3 CH 3  CH 3 ─CH─CH─CH 3 STEP 1 Longest chain is butane. STEP 2 Number chain. CH 3 CH 3  CH 3 ─CH─CH─CH STEP 3 Locate substituents and name. 2,3-dimethylbutane

39 Pause Do active Learning ALE 1, # 7 -13