Molecular Models Activity KeysKeys Molecular Model's Activity .
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Transcript of Molecular Models Activity KeysKeys Molecular Model's Activity .
Molecular Models Activity
ammonia
hydrogen monochloride
trichloromethane
urea
propane
butane
nitrogen triiodide (video)
carbon tetrachloride
methane
water
ethane
ethyne
dihydrogen monosulfide
carbon dioxide
supplies
Bonding and Shape of Molecules
Number of Bonds
Number of Unshared Pairs Shape Examples
2
3
4
3
2
0
0
0
1
2
Linear
Trigonal planar
Tetrahedral
Pyramidal
Bent
BeCl2
BF3
CH4, SiCl4
NH3, PCl3
H2O, H2S, SCl2
-Be-
B
C
N
:
O
:
:
CovalentStructure
Lewis Structures
1) Count up total number of valence electrons
2) Connect all atoms with single bonds
- “multiple” atoms usually on outside
- “single” atoms usually in center;
C always in center,
H always on outside.
3) Complete octets on exterior atoms (not H, though)
4) Check
- valence electrons match with Step 1
- all atoms (except H) have an octet; if not, try multiple bonds
- any extra electrons? Put on central atom
- no unpaired electrons (free radicals)
Gilbert Lewis
Carbon tetrachloride
C ClClCl
Cl
CCl4
C109.5o
Cl
ClClCl
Carbon tetrachloride – “carbon tet” had been used as dry cleaning solventbecause of its extreme non-polarity.
Tetrahedral geometry
Methane
CHH
HH
C109.5o
H
HHH
Methane –The first member of the paraffin (alkane) hydrocarbons series. a.k.a. (marsh gas, CH4).
Tetrahedral geometry
Water
....
H HOBent
geometry
SO2
(-)
(+)
Polar molecule
Ethane
CH
CHH
HHH
space-filling molecule
ball-and-stickLewis dot notation
C2H4
molecular formula
C = 1s22s22p2
Ethane
CH
CHH
HHH
space-filling molecule
ball-and-stickLewis dot notation
C2H6
molecular formula
Ethyne
CCH H CCH H
No octet
Stable octet
6 electrons = triple bond
CCH H
C2H2
CCH H
each C “feels” 6 electrons
each C “feels” 7 carbons
Ethyne – a.k.a. “acetylene”
Dihydrogen monosulfide
....
H HS
Bent
SO2
Carbon dioxide
O OC
Lineargeometry
C OOCO2
C OO
Ammonia
NH HH
N107o HH
H
..
NH3
..
HH
H
N
TrigonalPyramidalgeometry
NH HH
H
Amino Acids – Functional Groups
Amine Carboxylic AcidBase Pair
NH21- R- COOH
NH3NH21- NH4
1+
amine ammonia ammonium ion
NH
HH
:
NH
HH
H : 1+
NH
H
:
1-
:
H+ lose H+ H+
+
Hydrogen monochloride
H ClHCl
H Cl
(-)(+)
H Cl
Polar molecule
HCl(g) + H2O(l) HCl(aq)
hydrogenchloride
water hydrochloric acid
Trichloromethane
C ClClCl
H
CHCl3
C109.5o
H
ClClCl
C ClClCl
H
(-)
(+)
Polar molecule
Tetrahedral geometry
Urea
CON HH
NH H
CON HH
NH H
CO(NH2)2
NOT “di-urea”
Urea – The first organic compound to be synthesized (Wohler, 1828).
Propane
CH
CHH
CH
HHHH
C C C
HH
H
HH H H
H
C3H8
Butane
CH
CHH
CH
C HH
HHHHH - C - C - C - C - H
H H H H
H H H H
C4H10 C C C
HH
H
HH H H
HC
H
H
Nitrogen triiodide
NI II N
107o III
..
NI3
TrigonalPyramidalgeometry
Video clip:
(slow motion)
detonation of NI3
Supplies
15 black (carbon) 8 green (chlorine and iodine) 1 yellow (sulfur) 4 blue (oxygen) 4 red (nitrogen) 42 hydrogen (hydrogen) 67 bonds (bonds)
C Cl I S O N H
C ClClCl
ClCH
H HH
C OO
SH HC C HH
C ClClCl
H
H Cl
CCl4 CH4
CO2
C2H2
HClCHCl3
SH2
CH
CHH
CH
C HH
HHHHCH
CHH
CH
HHHH
NH HH
NI II
Decomposition of Nitrogen Triiodide
Decomposition of Nitrogen Triiodide
2 NI3(s) N2(g) + 3 I2(g)
NI3 I2
N2
C109.5o
H
HHH
N107o HH
H
..
O104.5o H
H
..
..
CH4, methane NH3, ammonia H2O, water
..
O
O
O
lone pairelectrons
OOO
O3, ozone
......
The VSEPR Model
O OC
Linear
The Shapes of Some Simple ABn Molecules
O OS
BentO O
S
O
Trigonalplanar
FF
F
N
Trigonalpyramidal
T-shaped Squareplanar
F FCl
F
F F
Xe
F FF
F
FP
F
F
Trigonalbipyramidal
Octahedral
FF
F
S
F
F
F
AB6
SO2
Brown, LeMay, Bursten, Chemistry The Central Science, 2000, page 305
Resources - Nomenclature
Objectives
Worksheet - binary cmpds: single charge cation - binary cmpds: single charge cation
Worksheet - ions in chemical formulas
Worksheet - ionic cmpds: polyatomic ions w multiple-charge cation - ionic cmpds: polyatomic ions w multiple-charge cation
Worksheet - ionic formulas (binary, polyatomic, transition)
Worksheet - traditional system of nomenclature
Worksheet - covalent binary cmpds: non-metal - non-metal - covalent binary cmpds: non-metal - non-metal
Worksheet - ionic cmpds: polyatomic ions - ionic cmpds: polyatomic ions
Outline ((general)
Worksheet - empirical and molecular
Worksheet - vocab (bonding) - vocab (bonding)
Activity - bonding pieces
Activity - molecular models
Activity - mole pattern
Worksheet - binary compounds
Worksheet - ions in chemical compounds
Textbook - questions
Worksheet - ionic binary cmpds: multiple charge cation - ionic binary cmpds: multiple charge cation
Worksheet - oxidation numbers and ionic cmpds - oxidation numbers and ionic cmpds
Worksheet - names and formulas of cmpds - names and formulas of cmpds
Worksheet - errors in chemical formulas and nomenclature
General Chemistry PP