Transcript VSPER Modeling Activity - Spokane Public Schools

Entry Task: Friday Nov 30th
QUESTION:
Provide the Lewis Dot for CO2
You have 5 minutes!
VSPER Modeling Activity
Guide to Predicting Molecular Shape
(VSEPR Theory)
STEP 1 Write the electron-dot structure.
STEP 2 Arrange the electron groups around
the central atom to minimize
repulsion.
STEP 3 Use the atoms bonded to the central
atom to determine the shape of the
molecule.
3
Linear
• 2 atoms attached to center atom
0 unshared pairs (lone pairs)
..
..
: Cl : Be : Cl :
..
..
• Bond angle = 180o
• Type: EX2
• Ex. : BeCl2
Trigonal Planar
• 3 atoms attached to center atom
• 0 lone pairs
• Bond angle = 120o
• Type: EX3
• Ex. : BF3
Tetrahedral
• 4 atoms attached to center atom
• 0 lone pairs
H
H
C
H
H
• Bond angle = 109.5o
• Type: EX4
• Ex. : CH4
Trigonal Pyramidal
• 3 atoms attached to center atom
• 1 lone pair
• Bond angle = 107o
• Type: EX3
• Ex. : NH3
Bent
• 2 atoms attached to center atom
• 2 lone pairs
bent
O
H
H
• Bond angle =
• General: E2X
• Ex. : H2O
Trigonal Bipyramidal
• 5 atoms attached to center atom
• 0 lone pairs
Cl
Cl P
• Bond angle =
– equatorial -> 120o
– axial -> 90o
• Type: EX5
• Ex. : PCl5
Cl
Cl
Cl
Octahedral
• 6 atoms attached to center atom
• 0 lone pairs
F
F
S
F
F
F
• Bond angle = 90o
• Type: EX6
• Ex. : SF6
F
Part 2- Construct the following
molecules
1. Do the electron dot arrangement
2. Do the Lewis structure
3. Provide a drawing/ name of
molecular shape
4. After section 5 go back and predict
whether the molecule is polar or
non polar