LESSON PLAN TEMPLATE FOR THE AGENDA FOR EDUCATION IN A DEMOCRACY. Name: Drew Parliment Date: October 30th

LESSON PLAN TEMPLATE FOR THE AGENDA FOR EDUCATION IN A DEMOCRACY Name: Drew Parliment Date: October 30th Unit Essential Question:_How can you predict the 3D structure and resonance of a molecule from its Lewis structure? Lesson Topic: VSEPR Model Class: AP Chemistry PLANNING THE LESSON With Democracy and Social Justice at the Center of Instruction Focusing on the National Network for Educational Renewal (NNER) Mission the 4-Part Agenda for Education in a Democracy EQUAL ACCESS ENCULTURATION NURTURING PEDAGOGY STEWARDSHIP To Knowledge In Democratic Society Safe and Caring for All of the Mission What are you and your students doing today to advance the 4-Part Mission? Connections: With which part(s) of the Agenda does this lesson connect most clearly? And how? STANDARDS (www.cde.state.co) Content: The student is able to use Lewis diagrams and VSEPR to predict the geometry of molecules, identify hybridization, and make predictions about polarity. AP Standards Literacy and Numeracy: Use logic and rhetoric to analyze and critique ideas Democracy and 21 st Century Skills: Demonstrate intellectual curiosity OBJECTIVES Content: SWBAT Understand the following phenomenon: geometry, Hybridization, polarity, Literacy and Numeracy: SWBAT predict the molecular geometries of various molecules based on the VSEPR model. Democracy and 21 st Century Skills: SWBAT predict the various molecular geometries that arise from each electron

resonance and bond order. domain geometry. ASSESSMENTS What is your evidence of achieving each objective? How will students know and demonstrate what they have learned in each of the areas, all of the objectives? Content: SWBAT predict bond geometry, predict what molecules will be polar, predict the hybridization in a bond, draw Lewis structures molecules with resonance and calculate bond order. Literacy and Numeracy: SWBAT answer the questions on VSEPR presented during the lecture. Democracy and 21 st Century Skills: SWBAT predict the molecular geometries before the slide for each domain geometry is shown. KEY VOCABULARY Content VSEPR, hybridization, domain, Lewis structure, resonance Literacy and Numeracy rhetoric Democracy and 21 st Century Skills Intellectual curiosity HIGHER ORDER QUESTIONS for this lesson Content What can molecular geometry tell us about a molecule? Literacy and Numeracy When can I be confident that I understand the material? Democracy and 21 st Century Skills What are the applications of this material? How might it relate to other subjects? LESSON FLOW This is the actual planning of the lesson activities. Time Anticipatory Set Purpose and Relevance Warm-up may include any of the following: hook, pre-assessment, introduction

to topic, motivation, etc. Pre-assessment Time Pre-Assessment Students are asked questions on electron domains and geometry to see what they remember from Earth System Science. Time Building Background Link to Experience: What are some different properties of chemicals? Link to Learning: How do you think scientists can predict these properties? Time Instructional Input Models of Teaching: Concept Attainment, Direct Instruction, Discussion, and Mastery Learning SIOP Techniques: I do, We do, You do. Guided Practice Students will be shown how to use VSEPR to make predictions and will then do so on their own. Reading, Writing, Listening, Speaking Independent Practice Students will have problems in their course packets that they will complete in future lessons. Time Accommodations, Modifications, and Student Adjustments Consider: multiple intelligences, learning styles, cultural and ability diversity, etc. If the activity is too advanced or too easy for some, how will you modify instruction so all students will learn?

If material is too advanced, I will slow down the pace to focus on that material (there are several days set aside to complete these slides). If material is too easy for some students, I will ask them to explain it to their peers. What accommodations will be needed and for whom? (IEP, 504, Special Needs) No accommodations needed. Time Review and Assessments of All Objectives Content: Students demonstrate their knowledge of VSEPR through questions throughout the lecture Literacy and Numeracy: Students demonstrate the proper logic when answering these questions. Democracy and 21 st Century Skills: Students are engaged and show an interest in the application of the material when answering questions and asking their own. Time Closure What will you and the students do at the end of the lesson or after a chunk of learning to synthesize, organize and connect the learning to the essential question(s)? Students will be given a discussion period to ask questions and improve their own understanding. Time Next Step The next class period will continue the slides from where I leave off.

Post-Lesson Reflection ( For the Teacher) 1. To what extent were all objectives achieved? 2. What changes would you make if you teach the lesson again? 3. What do you envision for the next lesson? 4. To what extent does this lesson achieve the Mission of the Agenda for Education in a Democracy? To what extent does this lesson achieve the 21 st Century Skills?

Objective: The student is able to use Lewis diagrams and VSEPR to predict the geometry of molecules, identify hybridization, and make predictions about polarity. Learning Targets: Understand the following phenomenon: geometry, Hybridization, polarity, resonance and bond order. Success criteria: Students will be able to predict bond geometry, predict what molecules will be polar, predict the hybridization in a bond, draw Lewis structures molecules with resonance and calculate bond order.

AP Chemistry, Chemical Bonding & Organics Objectives Upon completion of this unit, the students will be able to draw Lewis structures for atoms, ions, and compounds. know when to follow the octet rule and when exceptions to the rule apply. define multiple bonds and know where they exist. discuss the importance of bond polarity and electronegativity. define resonance structures and know where they exist. compare the relative strengths of different bonds. compare bond energies to enthalpies of reactions. predict molecular geometries. use the VSEPR model. determine where and which hybrid orbitals form: sp, sp 2, sp 3, sp 3 d, sp 3 d 2 differentiate between sigma (σ) and pi (π) bonds. describe molecular bonds (bonding orbitals and antibonding orbitals). define diamagnetism and paramagnetism. draw, model, and recognize isomerism. memorize the nomenclature of the alkane series. recognize, draw, and name simple unsaturated hydrocarbons and simple hydrocarbon derivatives (functional groups). define protein, carbohydrates, and lipids. Most Slides modified or taken from: John D. Bookstaver St. Charles Community College St. Peters, MO 2006, Prentice-Hall, Inc.

Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of bonding and nonbonding electron pairs we can easily predict the shape of the molecule.

What Determines the Shape of a Molecule? Simply put, electron pairs, whether they be bonding or nonbonding, repel each other. By assuming the electron pairs are placed as far as possible from each other, we can predict the shape of the molecule.

Electron Domains This molecule has four electron domains. We can refer to the electron pairs chemical bonds as electron domains. In a double or triple bond, all electrons shared between those two atoms are on the same side of the central atom; therefore, they count as one electron domain.

Valence Shell Electron Pair Repulsion Theory (VSEPR) The best arrangement of a given number of electron domains is the one that minimizes the repulsions among them.

Electron- Domain These are the electron-domain geometries for two through six electron domains around a central atom.

Electron-Domain All one must do is count the number of electron domains in the Lewis structure. The geometry will be that which corresponds to that number of electron domains.

The electron-domain geometry is often not the shape of the molecule, however. The molecular geometry is that defined by the positions of only the atoms in the molecules, not the nonbonding pairs.

Within each electron domain, then, there might be more than one molecular geometry.

Linear Electron Domain In this domain, there is only one molecular geometry: linear. NOTE: If there are only two atoms in the molecule, the molecule will be linear no matter what the electron domain is.

Trigonal Planar Electron Domain There are two molecular geometries: Trigonal planar, if all the electron domains are bonding Bent, if one of the domains is a nonbonding pair.

Nonbonding Pairs and Bond Angle Nonbonding pairs are physically larger than bonding pairs. Therefore, their repulsions are greater; this tends to decrease bond angles in a molecule.

Multiple Bonds and Bond Angles Double and triple bonds place greater electron density on one side of the central atom than do single bonds. Therefore, they also affect bond angles.

Tetrahedral Electron Domain There are three molecular geometries: Tetrahedral, if all are bonding pairs Trigonal pyramidal if one is a nonbonding pair Bent if there are two nonbonding pairs

Trigonal Bipyramidal Electron Domain There are two distinct positions in this geometry: Axial Equatorial

Trigonal Bipyramidal Electron Domain Lower-energy conformations result from having nonbonding electron pairs in equatorial, rather than axial, positions in this geometry.

Trigonal Bipyramidal Electron Domain There are four distinct molecular geometries in this domain: Trigonal bipyramidal Seesaw T-shaped Linear

Octahedral Electron Domain All positions are equivalent in the octahedral domain. There are three molecular geometries: Octahedral Square pyramidal Square planar

What is the molecular 1.Linear 2.Bent 3.Trigonal planar 4.Tetrahedral 5.Pyramidal geometry of NO 2?

What is the molecular geometry of XeF 4? 1.Linear 2.Trigonal planar 3.Square planar 4.Tetrahedral 5.Pyramidal

Using VSEPR, predict the molecular geometry of SF 4. 1. T-shaped 2. Seesaw-shaped 3. Trigonal bipyramidal 4. Linear

Correct Answer: 1. T-shaped 2. Seesaw-shaped 3. Trigonal bipyramidal As indicated in the illustration, the molecular geometry of SF 4 is seesaw. 4. Linear

Larger Molecules In larger molecules, it makes more sense to talk about the geometry about a particular atom rather than the geometry of the molecule as a whole.

Larger Molecules This approach makes sense, especially because larger molecules tend to react at a particular site in the molecule.

1. The molecule is both linear and planar. 2. The molecule is not linear but is planar. 3. The molecule is linear but not planar. 4. The molecule is neither linear nor planar.

Polarity Last year we discussed bond dipoles. But just because a molecule possesses polar bonds does not mean the molecule as a whole will be polar.

Polarity By adding the individual bond dipoles, one can determine the overall dipole moment for the molecule.

Polarity

SO 2 : Polar or nonpolar? 1. Polar 2. Nonpolar

Correct Answer: 1. Polar 2. Nonpolar Clearly from the bond dipoles the molecule SO 2 will exhibit a net overall dipole, thus being a polar molecule.

Which are polar molecules? a. a and b b. a, b, and c c. a and c d. a, c, and d e. c and e

Overlap We think of covalent bonds forming through the sharing of electrons by adjacent atoms. In such an approach this can only occur when orbitals on the two atoms overlap.

Overlap Increased overlap brings the electrons and nuclei closer together while simultaneously decreasing electronelectron repulsion. However, if atoms get too close, the internuclear repulsion greatly raises the energy.

1. Yes 2. No

Hybrid Orbitals But it s hard to imagine tetrahedral, trigonal bipyramidal, and other geometries arising from the atomic orbitals we recognize.

Hybrid Orbitals Consider beryllium: In its ground electronic state, it would not be able to form bonds because it has no singly-occupied orbitals.

Hybrid Orbitals But if it absorbs the small amount of energy needed to promote an electron from the 2s to the 2p orbital, it can form two bonds.

Hybrid Orbitals Mixing the s and p orbitals yields two degenerate orbitals that are hybrids of the two orbitals. These sp hybrid orbitals have two lobes like a p orbital. One of the lobes is larger and more rounded as is the s orbital.

Hybrid Orbitals These two degenerate orbitals would align themselves 180 from each other. This is consistent with the observed geometry of beryllium compounds: linear.

Hybrid Orbitals With hybrid orbitals the orbital diagram for beryllium would look like this. The sp orbitals are higher in energy than the 1s orbital but lower than the 2p.

Hybrid Orbitals Using a similar model for boron leads to

Hybrid Orbitals three degenerate sp 2 orbitals.

Hybrid Orbitals With carbon we get

Hybrid Orbitals four degenerate sp 3 orbitals.

Hybrid Orbitals For geometries involving expanded octets on the central atom, we must use d orbitals in our hybrids.

Hybrid Orbitals This leads to five degenerate sp 3 d orbitals or six degenerate sp 3 d 2 orbitals.

Hybrid Orbitals Once you know the electron-domain geometry, you know the hybridization state of the atom.

What is the hybridization of nitrogen in HNO 3? a. sp b. sp 2 c. sp 3 d. sp 3 d e. sp 3 d 2

Which kind of hybridization is about the central atom in PCl 5? a. sp 2 b. sp 3 c. sp 4 d. sp 3 d

Correct Answer: a. sp 2 b. sp 3 c. sp 4 d. sp 3 d The hybridization for PCl 5 is sp 3 d, as shown to the right.

What is the hybridization of sulfur in methyl mercaptan, CH 3 SH? a. sp b. sp 2 c. sp 3 d. sp 3 d e. sp 3 d 2

Valence Bond Theory Hybridization is a major player in this approach to bonding. There are two ways orbitals can overlap to form bonds between atoms.

Sigma ( ) Bonds Sigma bonds are characterized by Head-to-head overlap. Cylindrical symmetry of electron density about the internuclear axis.

Pi ( ) Bonds Pi bonds are characterized by Side-to-side overlap. Electron density above and below the internuclear axis.

Single Bonds Single bonds are always bonds, because overlap is greater, resulting in a stronger bond and more energy lowering.

Multiple Bonds In a multiple bond one of the bonds is a bond and the rest are bonds.

Multiple Bonds In a molecule like formaldehyde (shown at left) an sp 2 orbital on carbon overlaps in fashion with the corresponding orbital on the oxygen. The unhybridized p orbitals overlap in fashion.

Multiple Bonds In triple bonds, as in acetylene, two sp orbitals form a bond between the carbons, and two pairs of p orbitals overlap in fashion to form the two bonds.

How many sigma and pi bonds are in the molecule acetic acid, CH 3 COOH? a. 6 sigma bonds, 2 pi bonds b. 7 sigma bonds, 1 pi bond c. 7 sigma bonds, 2 pi bonds d. 8 sigma bonds, 0 pi bonds e. 8 sigma bonds, 1 pi bond

In the molecule C 2 H 4, how many sigma bonds ( ) and how many pi bonds ( ) are there? a. Five sigma, one pi b. Four sigma, two pi c. Six sigma, zero pi d. None of the above

Correct Answer: a. Five sigma, one pi b. Four sigma, two pi c. Six sigma, zero pi The sigma and pi bonds for C 2 H 4 are indicated in the illustration. d. None of the above

Delocalized Electrons: Resonance When writing Lewis structures for species like the nitrate ion, we draw resonance structures to more accurately reflect the structure of the molecule or ion.

Delocalized Electrons: Resonance In reality, each of the four atoms in the nitrate ion has a p orbital. The p orbitals on all three oxygens overlap with the p orbital on the central nitrogen.

Delocalized Electrons: Resonance This means the electrons are not localized between the nitrogen and one of the oxygens, but rather are delocalized throughout the ion.

The organic molecule benzene has six bonds and a p orbital on each carbon atom. Resonance

Resonance In reality the electrons in benzene are not localized, but delocalized. The even distribution of the electrons in benzene makes the molecule unusually stable.

Bond Order Describes the character of the bond (how much it resembles a single, double or triple bond). The Carbon-Carbon bonds in Benzene have ½ Bond Order, because they resemble a hybrid of single and double bonds. Orbital theory in the text goes into more detail, but it is beyond the scope of this class.

What is the bond order in O 2 2-? a. 0 b. 0.5 c. 1 d. 1.5 e. 2

Paramagnetism vs. Diamagnetism Paramagnetism: a substance is attracted into an inducing magnetic field Diamagnetism: a substance is repelled away from an inducing magnetic field In a magnetic field paramagnetic substances will be pulled in and therefore weigh more. Paramagnetism is associated with unpaired electrons (diamagnetism is associated with paired electrons) Paramagnetism is stronger, therefore if a substance has both paired and unpaired electrons it will exhibit net paramagnetism

Is molecular O 2 paramagnetic or diamagnetic? 1. Paramagnetic 2. Diamagnetic

Correct Answer: 1. Paramagnetic 2. Diamagnetic O 2 is diamagnetic because each molecule contains two unpaired electrons.

Drew Parliment October 30 th lesson Reflection 11/25/14 For this lesson, I presented on molecular orbitals to Joe Anastasia s AP chemistry class. I felt going into this lesson that I had a closer relationship to the students in this class than in the general chemistry class. The AP students asked very interesting questions that went beyond the material they were learning, connecting it with other fields of study, which would often draw me into fascinating discussions that I deeply hope stoked the flames of their scientific curiosity. For this lesson, I lectured on slides that the science department had collaborated on for this material. Although I planned to cover more material, the class did not have as strong of a background in molecular shapes as Mr. Anastasia had anticipated, so that became the focus of the lesson. In addition to simply lecturing on the material, I implemented molecular modeling kits to show the shapes created and, as per Mr. Anastasia s recommendation, I asked students to predict the molecular geometries that could arise from each electron domain geometry. For this lesson, Mr. Anastasia advised that I practice my lecture more ahead of time and that I use more higher level questions to instill critical thinking. This first piece of advice would have likely helped my overall confidence in my ability to present. I was unsure how much of the material I would be able to get to and what background students would have for the material, so I was unsure how to prepare. To prepare, I edited the slides to fit what I wanted to cover, and took brief notes on what I wanted to cover on each slide. Had I then practiced making these points out loud, I likely would have delivered them more clearly, and perhaps been able to cover more content. Higher level questioning was also an issue in my first lesson, and is one that I will need to remember when assessing students in the future. The slides contained several multiple choice questions

asking for the molecular geometry of various molecules, and I asked students to first work on these problems individually, and then discuss them as a class. Although this assessment was effective of demonstrating that students had absorbed the facts of the lesson, a follow-up discussion asking students why they felt this information was important would have engaged students in the higher level reasoning behind the lesson. This lesson has further demonstrated what I need to improve as a teacher. I did feel that I was affected at adjusting the lesson to the needs of the class, since it was clear that molecular geometry needed to be covered in more depth than either of us expected. During the lesson, I worried that I was getting the class behind schedule, but Mr. Anastasia thanked me after the lesson for giving that topic extra attention, since glossing over it would have caused further problems down the line.

Drew Parliment Traditional Assessment 12/12/14 AP Chemistry orbitals and bonding test Standard: The student is able to use Lewis diagrams and VSEPR to predict the geometry of molecules, identify hybridization, and make predictions about polarity. Objective: The students are expected to demonstrate their knowledge of molecular orbitals, bonding and VSEPR to evaluate polarity, bond order and geometry.

Bond Geometry For the following molecules, state the number of electron domains, and the number of lone pairs on the central atom. 1) CCl 2 H 2 2) H 3 O + 3) OH - 4) H 3 O 4 P 5) NH 3 For the following molecules, state the ELECTRON DOMAIN GEOMITRY: 6) PH 3 7) CO 2 8) XeF 6 9) CH 4 10) CH 2 O For the following molecules, state the MOLECULAR GEOMETRY: 11) XeF 4 12) NH 3 13) CO 14) CCl3H 15) H 2 O

16) What are the geometries about each the three central atoms in the above molecule? Predict whether the following molecules would be polar. 17) H 2 S 18) ClCH 4 19) CO 2 20) H 3 O + 21) CCl 4 For each of the following molecules, predict the hybridization on the central atom. 22) CF 4 23) XeF 6 24) CS 2 25) CH 2 O 26) NH 3

Draw the other resonance structures of each molecule. 27) 28) 29) 30)