Electronegativity - Dipole, VSEPR Shape, Symmetry, … · Electronegativity - Dipole, VSEPR Shape,...
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electronegativity For our purposes use the definitions in the chart. The most polar bond determines the polarity of a molecule (i.e. if a compound contains one non-polar, and one polar bond the molecule, as a whole, is considered to be polar) % ionic character ΔEN polarity 0 – 10 0 – 0.5 non-polar 10 – 50 0.5 – 1.7 polar (covalent) 50 – 100 1.7 + ionic A B C D E F G Molecule Lewis structure Draw shape. Indicate bond dipoles ΔEN of bonds Polarity of bonds (ignore shape) Symmetrical molecule? (i.e. all pulls cancel out) Polarity of molecule 1. NH 3 3.1 – 2.1 = 1.0 polar No polar 2. N 2 3. HBr H Br 4. OCl 2 5. SF 6 H 6. SO 2 7. SiCl 4 8. CF 2 Cl 2 C-F: C-Cl: 9. XeF 4 Note: the EN for Xe is 2.6 10. C 2 H 4 C-C: C-H: Q – which binary (two element) compound would have the greatest ΔEN? H H N N N Br H F S F F F F F S O O O S O C F F Cl Cl Si Cl Cl Cl Cl H C C H H H
Transcript of Electronegativity - Dipole, VSEPR Shape, Symmetry, … · Electronegativity - Dipole, VSEPR Shape,...
electronegativity
For our purposes use the definitions in the chart. The most polar bond determines the polarity of a molecule (i.e. if a compound contains one non-polar, and one polar bond the molecule, as a whole, is considered to be polar)
% ionic character ΔEN polarity 0 – 10 0 – 0.5 non-polar 10 – 50 0.5 – 1.7 polar (covalent)
50 – 100 1.7 + ionic
A B C D E F G
Molecule Lewis structure Draw shape. Indicate bond
dipoles
ΔEN of bonds
Polarity of bonds (ignore
shape)
Symmetrical molecule? (i.e. all pulls cancel out)
Polarity of molecule
1. NH3
3.1 – 2.1 = 1.0 polar No polar
2. N2
3. HBr H Br
4. OCl2
5. SF6
H
6. SO2
7. SiCl4
8. CF2Cl2
C-F:
C-Cl:
9. XeF4 Note: the EN for Xe is 2.6
10. C2H4 C-C:
C-H:
Q – which binary (two element) compound would have the greatest ΔEN?
H H N
N N
Br H
FS
F
F F F
F
S O O
O S O
C F F
Cl Cl
Si Cl
Cl Cl
Cl
H C C
H
H H
Electronegativity: Answer key
For our purposes use the definitions in the chart. The most polar bond determines the polarity of a molecule (i.e. if a compound contains one non-polar, and one polar bond the molecule, as a whole, is considered to be polar)
% ionic character ΔEN polarity 0 – 10 0 – 0.5 non-polar 10 – 50 0.5 – 1.7 polar (covalent)
50 – 100 1.7 + ionic
A B C D E F G
Molecule Lewis structure Draw shape. Indicate bond
dipoles
ΔEN of bonds
Polarity of bonds (ignore
shape)
Symmetrical molecule?
Polarity of molecule
1. NH3
3.1 – 2.1 = 1.0 polar No polar
2. N2 No dipole
3.1 – 3.1 = 0 non-polar Yes non-polar
3. HBr H Br
2.8 – 2.1 = 0.7 polar No polar
4. OCl2
3.5 – 2.9 = 0.6 polar No polar
5. SF6 All away from centre
4.1 – 2.4 = 1.7 polar / ionic Yes non-polar
H
6. SO2 3.5 – 2.4
= 1.1 polar No polar
7. SiCl4 All away from centre
2.9 – 1.8 = 1.1 polar Yes non-polar
8. CF2Cl2 All away from centre
C-F: 4.1 – 2.5 = 1.6
C-Cl: 2.9 – 2.5 =0.4
polar
non-polar
No (yes if you think just about shape, but no
because Cl and F are different)
polar
9. XeF4 All away from centre
(4.1 – 2.6 = 1.5) (polar) Yes non-polar
10. C2H4 (small dipoles) C-C: 2.5 –
2.5 = 0 C-H: 2.5 – 2.1 =0.4
non-polar
non-polar Yes non-polar
Q1 – which binary (two element) compound would have the greatest ΔEN? FrF - ΔEN = 4.1 - 0.9 = 3.2 (ionic)
H H N
N N
Br H
FS
F
F F F
F
S O O
O S O
O Cl Cl
F Xe
F
F F
C F F
Cl Cl
Si Cl
Cl Cl
Cl
H C C
H
H H
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