Writing and Balancing Chemical Equations
Name
Period
Unit 5 – HW 1 Worksheet (Goals 2 – 4)
1. Describe the following word equation with a statement or sentence: Iron + Oxygen  iron (III) oxide
2. In a chemical equation, what is the purpose of the arrow?
3. How are the symbols (s), (l), (g) and (aq) used in an equation?
4. What is a catalyst and where is it shown in a chemical equation?
3. Describe a Combination Reaction:
4. Describe a Decomposition Reaction:
5. Describe a Single Replacement Reaction:
6. Describe a Double Replacement Reaction:
7. Describe a Combustion Reaction:
8. When a “hydrocarbon” is a reactant in a combustion reaction, _________________ and ___________________
are the products.
9. An element like magnesium can also react with oxygen. Give an example of a combustion reaction involving an
element as one of the reactants.
10. Match the generic equations given with their reaction type:
a. RS  R + S
_________________________________
b. R+S- + T+U-  R+U- + T+S-
_________________________________
c. CxHy + ?O2  ?CO2 + ?H2O
_________________________________
d. R + S  RS
_________________________________
e. T + RS  TS + R
_________________________________
11. Write the Law of Conservation of Mass –
12. Balance the following equations:

KNO3
KNO2 +

Al
+
HCl
CO
+
O2 
C4H10
+
Th(NO3)4

H2O2
Pb(NO3)2
+
K3PO4
H2O
PBr3
+
H2O
Na
+
H2O
CO2
H2


H2O
Th3(PO4)4
+
KNO3

PbCl2
NaNO3
+
H2O
O2
NaCl

+

+
+
O2
+
CO2

+
O2
AlCl3
O2
CH4
Classify reaction type:
CO2
H3PO3
NaOH
+
+
+
HBr
H2
13. Complete each of the following descriptions by writing the balanced chemical equation with chemical formulas
and symbols. Refer to the text for help with symbols and formulas.
When metallic iron is dropped into a solution of hydrochloric acid, bubbles of hydrogen gas and an iron (II)
chloride solution are produced.
Lithium metal burns in the presence of oxygen gas to generate solid lithium oxide.
Solid calcium carbonate will react with sulfuric acid (H2SO4) to form solid calcium sulfate, carbon dioxide, and
water.
Solid copper (II) chloride will react with a phosphoric acid (H3PO4) solution to form copper (II) phosphate and
hydrogen chloride, both in solution.
Hydrogen peroxide solution will react in the presence of a manganese dioxide catalyst to generate water and
oxygen gas.