Covalent bond worksheet

Chem Level 3: Covalent bonding worksheet : Page 1
Complete the following table as shown for Br2. Name_______________________________
The dots are the total number of valence electrons for the molecule. Arrange to make all
atoms "happy" (octet). If there are not enough dots, try double or triple bonds.
Molecular Orbital electron dot structural shape of polar or non-polar
formula sharing diagram diagram formula molecule bond molecule
Br2 Br !" !" !" ! .. .. Br–Br linear non- non-
(8+8 = 4s 4p : Br : Br : polar polar
16 dots) Br !" !" !" " ¨ ¨
4s 4p
BrF
H2S
OF2
PH3
CCl4
CS2
(2 double
bonds)

Worksheet: Dot Diagram Practice Page 2
1. Complete the following dot diagrams and write the structural formula for each compound.
( Hint: Carbon always makes a total of 4 bonds (4 single, 2 single and 1 double, etc. )
CH4
methane
(4+4 =
8 dots)
C2H6
ethane
C2H4, ethene
(1 double bond)
H
..
H : C : H
..
H
H H
H C C H
H H
H H
H C C H
H
|
H - C - H
|
H
ClCHF2
freon
CH2O
formaldehyde
(1 double bond)
CH3OH
methanol
F
H C Cl
F
H
H C O
H
H C O H
H
C2H2
acetylene
(1 triple bond)
H C C H
HCOOH
formic acid
(1 double bond)
H C O H
O
2. Draw the dot diagrams and write the structural formula for these compounds and polyatomic ions.
Same principle: Dots = total number of valence electrons. Negative ions add extra elctron(s), Positive
ions take away electron(s) Watch out for double and triple bonds!
OH –
hydroxide
ion (6+1+1
= 8 dots)
NH2 –
amide ion
BrO2 –
bromite ion
CN -
cyanide ion
..
: O : H
˙˙
H N H
O Br O -
[ C N ] -
[ O - H ] -
NH4 +
ammonium
ion
SO3 –2
sulfite ion
N2O
O
O S O
O
H
H N H
H
N N
-2
CO carbon
monoxide
POCl
O
O
C
P Cl
NO3 –
nitrate ion
O N O
O
-

Level 2 Chemistry Name _________________________page 3
Covalent bonding worksheet (use your VSEPR chart to answer the following)
1. Calculate the bond energy of the following molecules (add up the bond energies).
a. NH3 b. Br c. H
| |
Br– C – Cl
H – C = O
|
Cl
2. Which of the following molecules is the most stable (highest bond energy) The least stable
(lowest bond energy)
H – F H – Br H – I H – Cl
3. Calculate the electronegativity difference for the follwoing bonds. Then identify each as
non-polar, polar or ionic . If Polar or ionic, identify the + and – or !+ and !– element in each.
(The negative atom has the higher electronegativity).
a. H – I e. O – O
b. Li – I f. C – Cl
c. Ca – Cl g. H – O
d. I – I h. Na – O
4. What is the shape of the following molecules Is each molecule polar or non-polar For
polar molecules, identify the ! + and ! – part of each molecule.
.. .. .. .. .. .. ..
a. : I : I : c. : Cl : O : Cl : e. : Br : F :
˙˙ ˙˙ ˙˙ ˙˙ ˙˙ ˙˙ ˙˙
.. .. .. ..
..
: F :
.. .. ..
b. : Cl : P : Cl : d. H : C : : O : f. : F : C : F :
˙˙ ˙˙ ˙˙ ˙˙ ˙˙ ˙˙ ˙˙
: Cl : H : F:
˙˙
˙˙

Level 2 Chemistry page 4
Review sheet for Covalent Bonding
1. a. What are two differeneces between ionic bonding and covalent bonding
b. What are two similarities between ionic bonding and covalent bonding
2. Write the orbital notation electron sharing diagram for the covalent compound Cl2S.
3. Fill in the following chart for these covalent compounds.
ClF
Dot structural shape type of molecule
diagram formula (polar or non-polar)
H2Se
CH2Cl2
ClO -
4. H–Br Is the bond polar, non-polar or ionic
5. Acetylene, H–C"C–H, is a linear molecule. Is this molecule polar or non-polar Why