1. Molecular Shapes Polarity

2. Make sense of problem and persevere in solving them
Objective
Today I will be able to:
Predict the molecular shape of a molecule using the VSEPR theory
Predict the polarity of molecules based on the molecular shape
Evaluation/ Assessment
Informal assessment – Listening to group interactions as they completethe molecular shapes lab.
Formal Assessment – Analyzing student responses to the exit ticket and the exam.
Common Core Connection
Make sense of problem and persevere in solving them
Reason abstractly and quantitatively
Use appropriate tools strategically
Look for and make use of structure

3. Lesson Sequence Warm – Up Explain: Molecular Polarity (Day 1)
Elaborate: Molecular Shapes Lab Polarity (Day 1)
Formal and informal assessment
Explain: Formal Lewis Structure Rules (Day1)
Elaborate: Lewis Structure Practice (Day 2)
Evaluate: Exit Ticket
Formal assessment

4. Warm – Up (Day 1)
Which shape has the largest bond angle? What is this shape called?
How many lone pairs and bonds formed are in the trigonal pyramidal shape?
Draw the molecular shape for phosphorus pentachloride

5. Warm-Up (Day 2)
Draw the lewis structure for XeF4 How many lone pairs are around the central atom? How can you tell if a molecule is polar or nonpolar?

6. Objective Today I will be able to:
Predict the molecular shape of a molecule using the VSEPR theory
Predict the polarity of molecules based on the molecular shape

7. Homework
Molecular Shapes Quiz Friday, December 19

8. Agenda Warm-Up Polar Molecules Notes (Day 1)
Predicting Polarity in Molecular Shapes Lab (Day 1)
Formal Lewis Structure Notes (Day 1)
Lewis Structure Practice (Day 2)
Exit Ticket

9. Molecular Shapes Lab

10. Molecular Shapes Lab Directions
Draw a Lewis Dot Structure for the molecule
Make a model using the kit and draw the shape on your paper
Write the shape name
Write the bond angle
Skip POLARITY for now, and we will come back to this part
Be careful with the kits, do not drop or lose pieces!

11. Polarity

12. A molecule will be nonpolar if…
All of the terminal atoms (or groups) are the same
If all of the terminal atoms (or groups) are symmetrically arranged around the central atom
The terminal atoms (or groups) have the same charges
Example: CO2
CO2 – no charge on either side (dipole) no attraction, reason it is a gas at room temperature

13. A molecule will be polar if…
One or more terminal atoms differ from each other
The terminal atoms are not symmetrically arranged
Polar molecules will have one slightly positive end and one slightly negative end
Example
H2O
NH3

14. Polarity Examples

15. Molecular Shapes Lab Revisit the molecular shapes lab
Fill out the column labeled polarity
Please ask questions!

16. Formal Lewis Structure Drawing Rules

17. Rules Count the total number of valence electrons in the molecule
Draw the molecule and show all single bonds around the central atom
Using lone pairs, complete the octets around the non- central atoms
Count the total number of electrons on the molecule
Determine if you need to add a double or triple bond
Add extra electrons to the central atom

18. Expanded Octets

19. What shapes allow for an expanded octet?
Trigonal Bipyramidal
Octahedral

20. Draw the Lewis Structures for the following molecules
Determine the shape
Determine if the molecule is polar or nonpolar
CH3Cl
CH2O
BeCl2
BCl3
PF5
SF6
XeF4
SF4
ICl3

21. Lewis Structures for IonsK+
ClO2-1
CN-1
CO32-
SO42-

22. Lewis Structures Part III
CH4
NF3
H2S
C2H4
PF3
CF3Cl
H2S