CHEMICAL BONDING WARM-UP
Answer the following questions INDEPENDENTLY!
A
B
C
D
E
Identify the shape:
Draw the following and predict the Shape of the Following:
(1) H2S
(2) CBr4
Identify the shape:
Draw the following and predict the Shape of the Following:
(1) H2S - Bent
(2) CBr4 -Tetrahedral
A) Bent
B) Trigonal Pyramidal
C) Linear
D) Trigonal Planar
E) Tetrahedral
CHECK YOUR ANSWERS and DISCUSS ANYTHING YOU MISSED:
HOMEWORK CHECKCheck your homework answers against the keys provided on the next two slides.
HOMEWORK REVIEW:
VSEPR THEORY PRACTICE WORKSHEET
TODAY’S OBJECTIVES
WHAT YOU WILL LEARN TODAY
Objectives
Identify bond strengths based upon type of bond.
Define polarity
Apply VSEPR theory to predict the overall polarity of a molecule.
Predict the properties of a molecule based on the type of molecule (Ionic, NPC, PC, Metallic)
IDENTIFY BOND STRENGTHS BASED UPON TYPE OF BOND
Bonds have lengths and strengths! Ionic bonds- Strongest of all bonds!
Covalent Bonds Triple Bonds – shortest and stronger Double bonds Single bonds - longest and weakest of all
the bonds.
Arrange the following in order of increasing bond strength.
CO2
CCl4SrBr2
N2
CHECK YOUR ANSWERS ON THE NEXT SLIDE
Arrange the following in order of increasing bond strength.
CCl4 – WEAKEST – SINGLE COVALENT
CO2 -- Double Covalent
N2 --- Triple Covalent
SrBr2 Ionic – STRONGEST!!
DEFINE POLARITY
DISCUSS WHAT THESE PICTURES
HAVE IN COMMON
What Does This Represent???(Think Electronegativity!!)
Polarity
Polarity is defined as the unequal distribution of electrons.
But what does that actually mean?
Polar molecules have a slightly positive end and a slightly negative end.
Nonpolar molecules have a consistent charge throughout and thus no charged poles (ends).
POLAR and NONPOLAR DO NOT MIX!!!!
POLAR BONDS create special properties due to small charges.
PUT THIS IN YOUR NOTES!!!!!
DEMO: BACK TABLE
On the back table is a test tube filled with the following….
Water, Oil, and Food Coloring
Which items are Polar and which are NON-Polar?
(Hint: Research to determine the polarity of water) Check Your Answers On The Next
Slide
DEMO: BACK TABLE
On the back table is a test tube filled with the following….
Water, Oil, and Food Coloring
Which items are Polar and which are NON-Polar?
Water and Food Coloring are BOTH POLAR as they mix together. The oil is NONPOLAR causing it to not mix with the water.
Check Your Answers On The Next Slide
APPLY VSEPR THEORY TO PREDICT THE OVERALL POLARITY OF A MOLECULE.
How do you know if a molecule is polar? COPY THIS INTO YOUR NOTES
Step 1: Draw Lewis Structure & Determine the shape
Step 2: Predict the polarity of the molecule based on the following. Bent, and trigonal pyramidal molecules are ALWAYS
polar. (think about WHY they are bent…lone pairs)
Tetrahedral, trigonal planar, and linear are usually nonpolar. But can be polar, IF and ONLY IF there are 3 or more
different elements. Ex. CH4 (NonPolar) vs. CH2F2 (Polar)
Examples – Work As A Team
Determine if the following molecules are polar or non-polar: NH3
CSeF2
CO2Check Answers On The Next Slide ---
Examples – Work As A Team
Determine if the following molecules are polar or non-polar: NH3 Polar
CSeF2 Polar
CO2 Non-Polar
You Try - Work Independently
Determine if the following molecules are polar or non-polar.
NF3
SO2
CH2I2
You Try - Work Independently
Determine if the following molecules are polar or non-polar.
NF3 POLAR
SO2 POLAR
CH2I2 POLAR
PREDICT THE PROPERTIES OF A MOLECULE BASED ON THE TYPE
(IONIC, NPC, PC, METALLIC)
Copy this chart and complete as you read the next few slides
Type of Bond
Conduct Electrici
ty
DissolveIn
water?
State at Room Temp
IONIC
METALLIC
POLAR
NON-POLAR
Properties of Ionic Substances Hard Brittle A solid at room temperature Very high melting points (≈800C) Very high boiling points Soluble in water (think SALT) Conduct electricity when dissolved in
water or as a liquid.
Properties of Metals
Shiny Solid at room temperature. Very very high melting point (≈1000C) Very Very high boiling point Insoluble in water (does your gold necklace
wash away when you shower?)
Conduct electricity Malleable and ductile (think COPPER)
Properties of Polar Molecules
Typically a liquid at room temperature. Low melting points (≈20C) Medium boiling points Soluble in water (think SUGAR) Not a of conductor electricity
Properties of Non-polar molecules
Typically a gas at room temperature. Very low melting (≈-100C) Very low boiling points Insoluble in water (think Oxygen) Not a conductor of electricity.
Here’s What You Should Have Learned
Type of Bond
Conduct Electricit
y
Dissolve
State at Room Temp
IONIC Y Y SolidMETALLIC Y N Solid
POLAR N Y Liquid
NON-POLAR N N Gas
Steps for determining properties.
Step 1: Draw the Lewis structures Step 2: Predict the shape Step 3: Based on the shape determine
the polarity Step 4: Use polarity to determine
properties
Given CO2
Work Together To Answer The Following Questions:
What is the overall shape? Using this shape, what type of bond is present?
Ionic, Metallic, Polar or Nonpolar? Given the shape, determine the following:
What is the state of matter at room temp? Will it conduct electricity Will it dissolve in water?
Check Your Answers On The Next Slide
Given CO2
Work Together To Answer The Following Questions:
What is the overall shape? Linear Using this shape, what type of bond is present?
Ionic, Metallic, Polar or Nonpolar? Nonpolar Given the shape, determine the following:
What is the state of matter at room temp? Gas Will it conduct electricity No Will it dissolve in water? No
PULLING IT ALL TOGETHER
Copy and complete the following table, working together as a team
Compound
Type of Bond?
(I, M, PC, PC)
Shape State of Matter
Conduct Electricity
?
Dissolve in Water?
CO2 NPC Linear Gas No No
PCl3
H2O
CCl4
MgCl2
Cl2
CH2Cl2
NH3
AlCl3
Compound
Type of Bond?
(I, M, PC, NPC)
Shape State of Matter
Conduct Electricity
?
Dissolve in Water?
CO2 NPC Linear Gas No No
PCl3 PC Trig Pyramidal
Liquid No Yes
H2O PC Bent Liquid No Yes
CCl4 NPC Tetrahedral Gas No No
MgCl2 Ionic Lattice Solid Yes Yes
Cl2 NPC Linear Gas No No
CH2Cl2 PC Tetrahedral Liquid No Yes
NH3 PC Trig Pyramidal
Liquid No Yes
AlCl3 Ionic Lattice Solid Yes Yes
YOU TRY IT -----
Compound
Type of Bond?
Shape State of Matter
Conduct Electricity
?
Dissolve in Water?
SrAt2
O3
SO3
HgZn -----
GeH2Br2
Type of Bond
Conduct Electricit
y
Dissolve State at Room Temp
IONIC Y Y Solid
METALLIC Y N Solid
POLAR N Y Liquid
NON-POLAR
N N GasWORK INDEPENDENTLY !!
YOU TRY IT -----
Compound
Type of Bond?
Shape State of Matter
Conduct Electricity
?
Dissolve in Water?
SrAt2 Ionic Lattice Solid Yes Yes
O3 PC Bent Liquid No Yes
SO3 NPC Trig Planar Gas No No
HgZn Metallic ----- Solid Yes No
GeH2Br2 PC Tetrahedral Liquid No Yes
Type of Bond
Conduct Electricit
y
Dissolve State at Room Temp
IONIC Y Y Solid
METALLIC Y N Solid
POLAR N Y Liquid
NON-POLAR
N N GasWORK INDEPENDENTLY !!
Objectives (Today You’ve Learned How To….)
Identify bond strengths based upon type of bond.
Define Polarity
Apply VSEPR theory to predict the overall polarity of a molecule.
Predict the properties of a molecule based on the type of molecule (Ionic, NPC, PC, Metallic)
HOMEWORK
BONDING WORKSHEET (WHOLISTIC VIEW)
HONORS…. OMIT INTERMOLECULAR FORCESSECTION UNTIL LATER
UNIT 4 QUIZ
When you’re finished, turn in paper and start on worksheet. Complete worksheet for homework!
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