CHE 120/140/170 Handout – Polar, Nonpolar or Ionic
Polar, Nonpolar or Ionic
There are two main classifications of bonds:
covalent or ionic. Within covalent bonds, there
are also two main classifications: polar and nonpolar. The first step to identify whether a
compound is polar, nonpolar or ionic is simply to be able to determine the difference between
ionic and covalent compounds.
Ionic compounds typically form when a nonmetal and a metal combine.
Of course, it is possible
to have all nonmetals in an ionic compound if polyatomic ions are present. Covalent compounds
form with all nonmetals or a nonmetal with a metalloid. Can you properly classify the following
compounds as ionic or covalent?
formula
name
classification
1.
RbI
rubidium iodide
_______________________
ionic
2.
H2O
water
_______________________
covalent
3.
Fe2(CO3)3
iron(III) carbonate
_______________________
ionic
4.
NO
nitrogen monoxide
_______________________
covalent
5.
SF4
sulfur tetrafluoride
_______________________
covalent
6.
NH3
ammonia
_______________________
covalent
7.
NH4Cl
ammonium chloride
_______________________
ionic
8.
NF3
nitrogen trifluoride
_______________________
covalent
9.
BF3
boron trifluoride
_______________________
covalent
10.
TiCl2
titanium(II) chloride
_______________________
ionic
magnesium hydroxide
_______________________
ionic
11. Mg(OH)2
12.
SiO2
silicon dioxide
_______________________
covalent
13.
CCl4
carbon tetrachloride
_______________________
covalent
14.
O3
ozone
_______________________
covalent
Now, to be able to classify the covalent compounds as polar or nonpolar, we must be able to
draw the compounds as they exist in three-dimensional space.
15. To be able to draw a compound in its threedimensional representation, we must first draw its what?
16. Now that we have that, we use what theory to
see how those bonds lie in three-dimensional space? VSEPR:
Lewis dot structure
Valence Shell Electron Pair Repulsion
Remember that we need to identify all areas of high electron density around the central atom.
These are the “groups.” Then, groups are arranged as far apart from each other as possible.
Polar Nonpolar or Ionic key.docx
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CHE 120/140/170 Handout – Polar, Nonpolar or Ionic
Below you will see that the VSEPR shapes for the covalent compounds on the front of this sheet
have already been drawn for you. Your job is to determine if the compound is polar or nonpolar.
Remember that a nonpolar compound can have polar bonds, but if a compound has no polar
bonds it cannot be polar. For each molecule, draw the appropriate vector by each polar bond;
then, if the molecule is polar, draw a vector (and circle it) showing the overall polarity of the
molecule. If the molecule is nonpolar, write “nonpolar” by it.
O
17.
F
H
H
B
F
F
22.
N
nonpolar
O
18.
23.
O
O
nonpolar
F
F
S
Cl
F
F
19.
Si
C
Cl
Cl
Cl
24.
nonpolar
N
H
H
H
20.
O
O
O
25.
nonpolar
N
F
F
(no polar bonds)
F
21.
Polar Nonpolar or Ionic key.docx
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