1. VESPR Theory and Molecular Shapes Lab

2. Make sense of problem and persevere in solving them
Objective
Today I will be able to:
Draw Lewis Structures to represent the valance electrons of atoms
Represent the formation of ionic and covalent compounds using Lewis Structures
Predict the molecular shape of a molecule using the VSEPR theory
Evaluation/ Assessment
Informal assessment – Listening to group interactions as they complete the illustrating ionic and covalent compounds practice and the molecular shapes lab.
Formal Assessment – Analyzing student responses to the exit ticket and the practice worksheets.
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: VSEPR Theory
Explore and elaborate: Molecular Shapes Lab
Informal Assessment
Evaluate: Exit Ticket
Formal assessment

4. Warm - Up What are the properties of Ionic compounds?
What are the properties of Covalent Compounds?
How do I determine the number of valence electrons an atom has?

5. Warm-Up (Day 2) What does VSEPR stand for?
What bond angles does a tetrahedral shaped molecule have?
Draw the lewis structure for N2
What shape and angle does this structure have?

6. Objective Today I will be able to:
Draw Lewis Structures to represent the valance electrons of atoms
Represent the formation of ionic and covalent compounds using Lewis Structures
Predict the molecular shape of a molecule using the VSEPR theory

7. Homework
STEM Fair Abstract Due Friday December 12

8. Agenda
Warm-Up
VESPER Notes
Molecular Shapes Lab
Exit Ticket

9. Drawing Lewis Structures

10. Lewis Structures
Visual representation of the number of valance electrons in an atom

11. How to draw Lewis structures
Write the symbol of the element
Pretend there are 4 sides
Use dots to represent the valance electrons around the symbol
Place one dot on each side of the element before you form pairs
Exception: If there are only 2 valance electrons, they both go on the same side

12. Lewis Structures
C 1s2 2s2 2p2 • • • C •

13. Lewis Structures
Examples
Mg 1s2 2s2 2p6 3s2 • Mg •

14. Lewis Structures
Cl 1s2 2s2 2p6 3s2 3p5 • • • • Cl • • •

15. [ ] • • • • • • • • Cl Lewis Structures -1 Cl 1s2 2s2 2p6 3s2 3p5

16. VSEPR Theory Notes

17. Valance – Shell Electron Pair Repulsion Theory (VSEPR)
In a small molecule, the pairs of valance electrons are arranged as far apart from each other as possible
Explains why atoms form certain shapes when they bond together

18. Linear
Bonds Formed: 2
Lone Pairs: 0
Bond Angle: 180o

19. Trigonal Planar
Bonds Formed: 3
Lone Pairs: 0
Bond Angle: 120o

20. Tetrahedral
Bonds Formed: 4
Lone Pairs: 0
Bond Angle: 109.5o

21. Trigonal Pyramidal Bonds Formed: 3 Lone Pairs: 1
Bond Angle: <109.5o

22. Bent (Tetrahedral) Bonds formed: 2 Lone Pairs: 2
Bond Angle: <109.5o

23. Bent (Trigonal Planar)
Bonds Formed: 2
Lone Pairs: 1
Bond Angle: <120o

24. Trigonal Bipyramidal Bonds Formed:5 Lone Pairs: 0
Bond Angle: 120o and 90o

25. Octahedral
Description:6
Lone Pairs: 0
Bond Angle: 900

26. Molecular Shapes Lab

27. 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!

28. Exit Ticket Draw the Lewis Structure for CO2
Determine the shape and bond angles of CO2 according to the VSEPR theory.

29. Exit Ticket – Mol Monday # 7
How many formula units of LiCl are in 2.30 moles of LiCl?