CHEM 10050
Sample Test
1.
Draw Lewis structures for the following molecules. (Show all lone pairs of
electrons where applicable).
a) H2Se
2.
b) CBr4
c) SO3
a) What is the geometry of CBr4, above? ___________________________
b) What are the bond angles in CBr4, above? ________________________
3.
Are the following molecules polar or nonpolar?
a) SiCl4 ____________________
b) H2O _____________________
c) CO2 _____________________
4.
Name the following binary molecular compounds:
a) N2O5 ________________________________
b) P4S3 ________________________________
c) NaH _________________________________
d) CO2 _________________________________
e) CO __________________________________
5.
6.
Balance the following equations by adding the appropriate coefficients where
necessary:
a)
PCl3
+
H2O

H3PO3
+
HCl
b)
Ca3P2
+
H2O

PH3
+
Ca(OH)2
Write the ionic equation and the net ionic equation for the following:
Cd(NO3)2 (aq)
7.
+
Na2S (aq)

2 NaNO3 (aq)
+
CdS (s)
The electronegativities for certain elements are shown below:
Atom
Electronegativity
C
N
O
Cl
F
H
2.5
3.0
3.5
3.0
4.0
2.1
Rank the following covalent bonds in order from most polar (1) to least polar (4):
C N
H Cl
H F
C O
____
____
____
____
8.
Classify the following reactions as either combination, decomposition, singlereplacement, or double-replacement:
a. FeCl2
b. 2 Au2O3 
c. AgNO3
2 NaCl
+
Fe(OH)2
4 Au + 3 O2
+ CsCl

d. SiCl4
+ 2 Mg 
e. 3 Mg
+ N2

f. 4 Mg + Fe3O4
9.

+ 2 NaOH
AgCl
2 MgCl2
_____________________
+
CsNO3
+ Si
Mg3N2

4 MgO
_______________________________
________________________________
_____________________
________________________________
+ 3 Fe
_____________________
True or False.
______If a molecule contains polar bonds, the molecule is always polar overall.
______Spectator ions do not undergo a change during a reaction.
______Nitrogen typically forms 2 covalent bonds and has 2 lone pairs of electrons.
______A double bond consists of a total of 4 electrons.
______Fluorine exists as a diatomic molecule.
______In the H-Cl bond, the H is partially positive, and the Cl is partially negative.
______The geometry of a molecule with 3 bonds and 1 lone pair of electrons is planar
triangular.
______Covalent bonds are stabilized by the attraction between 2 positively charged
nuclei.