Day 15­ Polarity
In a bond
pure covalent
NON­polar
Day 15­ Polarity
Ionic
Day 15­ Polarity
Day 15­ Polarity
Polar and Non Polar Molecules: Crash Course Chemistry #23 http://www.youtube.com/watch?v=PVL24HAesnc
Polarity Drops on a Penny Challenge Predict Team OIL vs. Team H2O
WINNERS!
Explain
POLAR
NON POLAR
Observe
Explain
Why does water sck to itself so strongly? It is a polar molecule.
Polar Molecule: a molecule that has a partial ­ charge ___________________________________ on one end and a ___________________________________ on the other end. partial + charge Diagram:
H
O
H
O
H
O
H
H
H
H
H
O
H bonding
Day 15­ Polarity
Polar Molecules
To be polar a molecule it must have polar bonds AND be ___________________ in shape.
asymmetrical
Asymmetrical molecules are either: 1) VSEPR shapes that are not symmetrical, like trigonal pyramidal and bent.
POLAR
2) Any VSEPR shape that has surrounding atoms with different electronegavies.
CF4
CHF3
NON POLAR
POLAR
BF3
BHF2
POLAR
NON POLAR
Non‐Polar Molecules
A non‐polar molecule is a molecule with neither a posive nor negave pole. Their shapes are symmetrical. Linear, trigonal planar and tetrahedral shapes can be symmetrical.
A molecule may have polar bonds but be non‐polar if the shape is symmetrical. Eg. CO2
NON Polar
molecule
polar
bond
polar
bond
Day 15­ Polarity
Properes of Polar and Non‐polar Molecules
Polar: Molecules aract each other due to the δ + and δ ­ ends causing them to have higher melng and boiling points, they sck to each other beer (higher surface tension, remember the penny acvity).
Non‐Polar: Molecules do not aract each other as much causing them to have lower melng and boiling points. Many are gasses at room temperature. Eg. O2(g)
Homework
TOMORROW
1) p. 94 # 6, 7, 8
2) Polar Bear Activity
3) VSEPR Big Sheet Right Column (polarity)
2:30­4:30
Library
Chem. Party!