Download unit 5b hw packet File - District 196 e

Chemistry
Name _________________________
Unit #5B Plan – Bonding Concepts and Carbon Chemistry
I)
II)
Assignments / Handouts
 Lewis structures and naming H-carbons
 Electronegativity chart
 Molecular shape guide
 Chemical bonding
 Chemical bonding homework
 Lewis structure intro
 Lewis and ball/stick structures ws
 Naming , drawing, building H-carbons ws
 Chapter 7 text assignment
 Polymer lab packet
 More TBA
(info – pg 2)
(info – pg 3)
(extra info - pg 4)
(notes – pg 5)
(required – pg 6)
(notes – pg 7)
(required – pg 7-8)
(required – pg 9-10)
(required – pg 11-12)
(required)
Text Support Chapter 7 (pg 196-223)
 Section 7.1
electronegativity and chemical bonds
 Section 7.2
valence electrons and chemical bonds
 Section 7.3
Lewis dot structures and molecular shapes
On-Line Text: www.lab-aids.com
Username:
evhs1
Password:
smeyer
(Log in as student in upper right corner. This is a common username and
password for all my chemistry students.)
III)
Learning Targets (I can…)
A)
Use an electronegativity chart to predict whether individual bonds in molecules are ionic,
polar covalent or nonpolar covalent.
B)
Draw electron dot diagrams (Lewis structures) to show the bonding of atoms in covalent
molecules.
C)
Build ball and stick structures to show the bonding of atoms in covalent molecules.
D)
Build, draw, and name hydrocarbons.
E)
Make and identify variations of the ethylene polymer.
IV)
Tentative Schedule
Mon
11/26 Polymer lab
Tue
11/27 Polymer lab wrap-up
Ionic, polar covalent, and nonpolar covalent bonding
Wed
11/28 Ionic, polar covalent, and nonpolar covalent bonding
Lewis (electron dot) structures
Thu
11/29 Ball and stick structures
Mon
12/3
H-carbons
Tue
12/4
Review
Wed
12/5
Exam #5B
HW Packet due
Hints for Drawing Lewis (Electron Dot) Structures
1. Add the number of valence electrons in each atom to determine the total number of
valence electrons. (For polyatomic anions, add one electron for each unit of negative
charge. For polyatomic cations, subtract one electron for each unit of positive charge.)
2. Put electrons around each atom. Start with the 4 base electrons before pairing electrons
up. (It is usually best to start with the atom that has the fewest valence electrons --excluding hydrogen.)
3. Atoms bond when electrons need to be shared to complete an octet around each atom.
4. The total number of electrons in Lewis structure should equal the total number of
valence electrons in the molecule (or ion).
 Hydrogen is “full” with 2 electrons. All other atoms need an octet of electrons to be
stable.
 A “shortage” of electrons usually means double or triple bonds are needed.
 Oh yes, there are exceptions.
Rules for Naming Hydrocarbons
1.
2.
3.
4.
Count carbons in longest chain to get prefix.
Check for single, double and triple bonds (or OH group). Use appropriate suffix.
Number carbons starting at the end nearest the double/triple bond or OH group.
Check for “branches”. (If there are no double/triple bonds or OH groups, number
carbons starting at end nearest the outermost “branch”.) Put in alphabetical order.
5. Put commas between consecutive numbers; dashes between numbers and words.
Alkane Roots (single bonds)
Methane
CH4
Ethane
C2H6
Propane
C3H8
Butane
C4H10
Pentane
C5H12
Hexane
C6H14
Heptane
C7H16
Octane
C8H18
Nonane
C9H20
Decane
C10H22
Branches
methyl
ethyl
propyl
butyl
(etc.)
fluoro
chloro
bromo
iodo
Functional Groups
Alkene --- double bond
Alkyne --- triple bond
Alcohol --- OH group
# of Branches
2 = di
3 = tri
4 = tetra
More Functional Groups (R or R’refers to carbon chain)
Ether
R-O-R’
Aldehyde
R-(C=O)-H
Ketone
R-(C=O)-R’
Carboxylic acid R-(C=O)-OH
Ester
R-(C=O)-O-R’
Amine
R-N(H2) or R-N(R’2) or R-N(R’H)
Aromatics
R-(C6H6)
-CH3
-C2H5
-C3H7
-C4H9
-F
-Cl
-Br
-I
Chemical Bonding Notes / Homework
Name ____________________
Conditions for Chemical Bonding
 Atoms must be physically close to each other

Atoms must attract each other
o Attractive forces > repulsive forces

Energy removal
o Energy is released (given off) as bonds formed
o Energy needs to be absorbed (added) to break bonds
Bond Length –distance between nuclei of 2 atoms when their attractive forces exceed their
repulsive forces by a maximum amount
Chemical Bond – electrons of 2 atoms are simultaneously attracted to the nuclei of both atoms
 Ionic Bond – unequal sharing of electron pairs between 2 nuclei

Nonpolar Covalent Bond – equal sharing of electron pairs between 2 nuclei

Polar Covalent Bond – somewhat equal (or unequal) sharing of electron pairs
between 2 nuclei
Chemical Bonding Homework - Use your electronegativity chart to predict if the following
molecules have ionic, polar covalent or nonpolar covalent bonds. (Look at the individual bonds -- -- not the overall symmetry.)
A. NaCl
G. CF4
B. BaCl2
H. CO2
C. OCl2
I. O2
D. H2O
J. NH3
E. CH4
K. H2S
F. MgO
L. Cl2
Lewis (Electron Dot) Structures Intro
Draw Lewis structures for each of the following covalent compounds. Your Hints for Drawing
Lewis Structures will be helpful.
H2O
CF4
NH3
Cl2
NH4+1
OH-1
Lewis (Electron Dot) Structures and Ball / Stick Structures
For each molecule:
 Draw its Lewis (electron dot) structures
 Build a ball/stick structure
 Identify each bond in the molecule as ionic (I), polar covalent (PC), or nonpolar covalent
(NPC)
Key for ball/stick structures
Color
Family
# of holes (bonding sites)
Black
Carbon
4
White
Hydrogen (only hydrogen)
1
Red
Oxygen
2
Green
Halogen
1
Orange/yellow
Nitrogen
3 (don’t use 4th hole)
1. CH4
C---H bond ________________
Ball/stick structure __________
2. CH2F2
C---H bond ________________
C---F bond ________________
Ball/stick structure __________
3. F2
F---F bond ________________
Ball/stick structure __________
4. PH3
P---H bond ________________
Ball/stick structure __________
5. C2H6
C---H bond ________________
C---C bond ________________
Ball/stick structure __________
6. C2H4
C---H bond ________________
C---C bond ________________
Ball/stick structure __________
7. C2H2
C---H bond ________________
C---C bond ________________
Ball/stick structure __________
8. CH3OH
C---H bond ________________
C---O bond ________________
O---H bond ________________
Ball/stick structure __________
9. O2
O---O bond ________________
Ball/stick structure __________
10. N2
N---N bond ________________
Ball/stick structure __________
Hydrocarbons
Naming – Name the following H-carbons using your rules on page #2 of this packet.
Isomers – Isomers have the same chemical formula, but a different structural formula.
Build, draw, and name the 2 isomers for C4H10.
Drawing / Building – Draw and build the following H-carbons.
1.
Pentane
5. 2-methyl butane
2. 2,2-dimethyl propane
6. 1-fluoro-3-methyl butane
3. 3 –ethyl hexane
7. 3,3-dimethyl hexane
4. 1-chloro ethane
8. 1,1,2,2 tetrafluoro ethane
Chapter 7 Text Assignment (pg 196-223)
1.
What is polarization?
2.
Consider the combination of 2 hydrogen atoms to form a covalent bond.
a. What are the attractive forces between the 2 hydrogen atoms?
b.
What are the repulsive forces between the 2 hydrogen atoms?
3.
In covalent bonds, electrons are _______________.
4.
In ionic bonds, electrons are __________________.
5.
Water is polar covalent.
a. Water is more positive near the _________________ part of the H2O molecule.
b.
Water is more negative near the _________________ part of the H2O molecule.
6.
What is electronegativity (EN)?
7.
Distinguish between polar covalent (PC) and nonpolar covalent (NPC).
8.
Define ionic bond.
9.
Define metallic bond/ (Note: metallic bonds are not “chemical” bonds.)
10. EN generally gets higher moving across the periodic table. Why?
11. EN generally gets higher moving up the periodic table. Why?
12. Why are the noble gases (most of them anyway) omitted from the EN table?
13. True or False: The number of valence electrons is the same as the family number using the 1A –
8A labeling system.
14. What stable family has an octet of valence electrons before any bonding occurs?
15. Most elements “want” to achieve an octet of valence electrons. Why does hydrogen “want” to
only achieve a duet of valence electrons?
16. How many electrons do each of the following need to gain to fill their octet of valence electrons?
Carbon ____
Nitrogen ____
Oxygen ____
Fluorine ____
17. What is a free radical?
18. How do antioxidants minimize the damage free radicals do to DNA?
19. Are the hydrogen atoms in water directly across from each other?
How does this affect the polarity of water?
20. Draw 2 isomers of C2H6O.
21. How many electrons are shared in each of the following types of bonds?
Single bond ____ Double bond ____
Triple bond ____
22. CO2 is a linear molecule which contains 2 polar bonds between carbon and oxygen. Why is the
overall CO2 molecule nonpolar?
23. What is a “lone pair” of electrons?
24. Distinguish between unsaturated fat and saturated fat.
25. What is the purpose of converting cis fats to trans fats in the partial hydrogenation process?