WAY BACK WEDNESDAY! Catalyst – March “Perfect 10” in 2010 1. Name two differences between...
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Transcript of WAY BACK WEDNESDAY! Catalyst – March “Perfect 10” in 2010 1. Name two differences between...
WAY BACK WEDNESDAY!Catalyst – March “Perfect 10” in 20101. Name two differences between
covalent and ionic compounds. 2. Ashley wants to see if using
mouthwash will make her teeth whiter. Identify the IV, DV, and 2 constants.
3. GEE Prep! True or False? A solar eclipse occurs when the sun passes between the earth and the moon, casting a shadow on part of the earth
Today’s Agenda
Catalyst Multiple Covalent Bonds Pause for Environmental
Issues/Activist Letters…DHMO...Oh no!
Let’s see what you know…Naming Covalent Compounds
Work Time Exit Question
Today’s Objectives
SWBAT draw Lewis Dot Structures for covalent compounds with multiple covalent bonds.
SWBAT name covalent compounds.
Quiz 3.1 Average
2nd Period: 63 4th Period: 59 5th Period: 53
Don’t get discouraged. Let’s change this on
Friday.
Multiple CovalentBonds
From Monday…Single Bonds
Single covalent bond: one pair of shared electrons (two electrons)
Atoms may be the same H2, F2, Cl2, Br2, I2, O2
Atoms may be different HF, HCl, HBr, HI
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LDS and Multiple Covalent Bonds
Key Point #1: Sometimes atoms must share more than one pair of electrons in order to become stable.
This results in double and triple bonds.
Double and Triple Bonds
Double covalent bond: two pairs of shared electrons (four electrons)
Triple covalent bond: three pairs of shared electrons (six electrons)
=
=
Example: Oxygen
Two oxygen atoms show up at the Homecoming Dance. Each oxygen atom has $6, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $12 for a couple atoms to go inside. How can both atoms get inside if they each only have $6???
They can share…electrons that is!!!
Try this one: Nitrogen
Two nitrogen atoms show up at the Halloween Party. Each nitrogen atom has $5, but it costs $8 per atom to go inside. The School of Elements is offering a discount for couples. It costs only $10 for a couple atoms to go inside. How can both atoms get inside if they each only have $5???
Model the bond formation of this happy couple!
Strengths of Bonds
TripleDoubleSingle
Key Point #2: Bond strength increases with number of bonds.
So….a double bond is stronger than a single bond, and a triple bond is stronger than a single or double bond.
Steps for Multiple Bond LDS’s
1. Write formula2. Number of valence
electrons (ve-)3. Number of octet
electrons (oe-) 4. Number of bonds5. Draw!
More Examples
O2
CO2
COCOCl2
Your Turn!
CS2
HClNOBr
Practice Time!
1. SO2
2. C2Br6
3. Se2
4. SiSBr2
5. Ge2H4
6. OS
The Environment…
In this class, I want you to learn the contents of basic chemistry…
However, I also want you to be able to understand the importance of chemistry in the environment.
There is a chemical, DHMO, that is especially ruining our environment in many ways… and something must be done. You should have already letters to the
government to help ban this awful, awful chemical
Surprise….
I have some DHMO with me today.
Does anyone want to see it??
Naming Covalent
Compounds
Differences between ionic and covalent
IONIC2 ions come
together!
Metal + Nonmetal
COVALENT
No ions!
Nonmetal + Nonmetal
Examples:
Na1+ + O2- CO2
Naming Ionic and Covalent Compounds
Key Point #3: When naming compounds, you must know which rules to use (ionic or covalent).
Ionic: Metal + Nonmetal Covalent: Nonmetal + Nonmetal
Let’s see what you learned yesterday…
5 minutes to fill in as many blanks as you can
Write in pencil (or be ready to cross out pen) so you can to fix errors after
Yo Yo! Let’s break it down!
IONICMetal + Nonmetal
Writing Formulas:Kriss Kross chargesNaming:2nd element ends in
–ide, ignore subscripts
COVALENTNonmetal + NonmetalWriting Formulas:Prefixes = subscript
#sNaming:Use prefixes, 2nd
element ends in -ide
A compound made from Lithium and Oxygen
How do we know if it is ionic or covalent? Metals and non-metals make ionic compounds
Naming Ionic Compounds
Ionic Bond
Ion: Li Ion: O
Li O
Ionic Bond
Ion: Li Ion: O
Li+ O2-
Ionic Bond
Ion: Li Ion: O
Li+ O2-
Ionic Bond
Cation: Li Anion: O
Li2O
Naming Ionic Compounds
MgO
Naming Ionic Compounds
MgO
Magnesium Oxide
Naming Ionic Compounds
CaCl2
Naming Ionic Compounds
CaCl2
Calcium Chloride
Naming Ionic Compounds
Al2O3
Naming Ionic Compounds
Al2O3
Aluminum Oxide
Naming covalent compounds
No Kriss Krossing!
Naming Covalent Compounds
PCl3
How do we know if this is a covalent compound? Is it between a metal and a non-metal? NO!!! Then, it is not ionic!!!
Is it between a non-metal and a non-metal? YES!!! Then, it is covalent!
Naming Covalent Compounds
Rule 1: If the first element has more than one atom, give it a
prefix.
Naming Covalent Compounds1 – mono- 2 – di-
3 – tri- 4 – tetra-5 – penta- 6 – hexa-7 – hepta- 8 – octa-9 – nona- 10 – deca-
Naming Covalent Compounds
PCl3
Naming Covalent Compounds
PCl3
Phosphorous
Naming Covalent Compounds
Rule 2: The second element always gets a
prefix, uses the root of the word and ends in -ide.
Naming Covalent Compounds
PCl3
Phosphorous
Naming Covalent Compounds
PCl3
PhosphorousTrichloride
Naming Covalent Compounds
Rule 3: The “o” or “a” at the end of
the prefix is dropped if the
element begins in a vowel.
Naming Covalent Compounds
N2O
Naming Covalent Compounds
Rule 1: If the first element has more than one atom, give it a
prefix.
Naming Covalent Compounds
N2O
Dinitrogen
Naming Covalent Compounds
Rule 2: The second element always gets a
prefix, uses the root of the word and ends in -ide.
Naming Covalent Compounds
N2O
Dinitrogen Monooxide
Naming Covalent CompoundsRule 3: The “o”
or “a” at the end of the prefix is dropped if the element begins
in a vowel.
Naming Covalent Compounds
N2O
Dinitrogen Monooxide
Naming Covalent Compounds
N2O
Dinitrogen Monoxide
Practice Time!
EXAMPLESCCl4As2O
SO
Sulfur Monoxide
WHITEBOARDS (?)
NO2
Nitrogen Dioxide
N2O
Dinitrogen Monoxide
P2O5
Diphosphorous Pentoxide
PCl5
PhosphorousPentachloride
NF3
NitrogenTrifluoride
Independent Practice Time
Lucky you!
Write the names and formulas…First! Decide if it’s ionic or covalent!
Write names
1. Na2O2. CO2
3. GeBr4
4. Na2CO3
5. Mg3P2
6. K2S7. N2S3
Write formulas
1. Carbon monoxide2. Barium nitrate3. Xenon difluoride4. Carbon tetrachloride5. Sodium carbonate6. Lithium fluoride7. Nitrogen trifluoride
Exit Question
1. Write the formula for: Silicon dioxide Dihydrogen monoxide
2. Write the name for the following compounds:
CO2
NH3