1. 1. Write a sentence that describes
this chemical reaction.
Na(s) + H2O(l) NaOH(aq) + H2(g)
Sodium metal and water react to form
sodium hydroxide and hydrogen gas.

2. 2. Sulfur burns in oxygen to form sulfur
dioxide. Write a skeleton equation for this
chemical reaction. Include appropriate
symbols from table 11.1.
S(s) + O2(g) SO2(g)

3. #3 Balance each equation. a. AgNO3 + H2S Ag2S + HNO3
First try balancing the silver,
Then balance the hydrogen
Balanced! On each side:
2 Ag
2 NO3
2 H
1 S

4. #3 Balance each equation.
b. Zn(OH) H3PO Zn3(PO4)2 + H2O 3 2 6
First try balancing the zinc,
Then balance the PO4
then balance the hydrogen
Balanced! On each side:
3 Zn
2 PO4
12 H
6 O

5. no coefficients needed
4. Rewrite these word equations as balanced
chemical equations.
a. hydrogen + sulfur hydrogen sulfide
b. iron (III) chloride + calcium hydroxide
iron (III) hydroxide + calcium chloride
H2 (g) S(s) H2S(g)
no coefficients needed 2 3 2 3
FeCl Ca(OH) Fe(OH) CaCl2

6. #5 Balance each equation:3 3
a. FeCl NaOH Fe(OH) NaCl 3
b. CS Cl CCl S2Cl2

7. #6 Write and balance this equation:
calcium hydroxide + sulfuric acid calcium sulfate + water
Ca(OH) H2SO CaSO4 + H2O 2

8. To write a word equation you need to
#7 Key Concept How do you write a word
equation?
example:
calcium hydroxide + sulfuric acid calcium sulfate + water
To write a word equation you need to
include the names of the reactants (left)
and products (right) on either side of an
arrow showing the direction of the reaction.

9. To write a skeleton equation you need to
#8 Key Concept How do you write a skeleton
equation?
example:
Ca(OH) H2SO CaSO4 + H2O
To write a skeleton equation you need to
include the correct formulas for the
the reactants (left) and products (right) of
an arrow showing the direction of the
reaction. This is NOT BALANCED YET

10. example: Ca(OH)2 + H2SO4 CaSO4 + H2O
#9 Key Concept Describe the steps in writing
a balanced chemical equation.
example:
Ca(OH) H2SO CaSO4 + H2O 2
1. Write out the correct formulas for
each compound in the reaction on both
sides of an arrow.
2. Add coefficients when needed in FRONT of
the compounds to give the same # and types
of elements on both sides of the equation.

11. ∆ ∆ #10. Write skeleton equations for these reactions: not balanced
a. Heating copper (II) sulfide in the presence of diatomic
oxygen produces pure copper and sulfur dioxide gas. ∆
CuS(s) O2(g) Cu(s) SO2 (g)
b. When heated, baking soda (sodium hydrogen carbonate)
decomposes to form the products sodium carbonate, carbon
dioxide, and water. ∆
NaHCO3 (s) Na2CO3(s) + CO2 (g) + H2O(g)

12. ∆ ∆ a. Fes) + Cl2(g) FeCl3(s) b. Al2(CO3)3 (s) Al2O3 + CO2(g)
#11 Write and balance equations for the fol-
lowing reactions:
Iron metal and chlorine gas react to
form solid iron (III) Chloride. ∆
a. Fes) Cl2(g) FeCl3(s) 2 3 2
Solid aluminum carbonate decomposes
to form solid aluminum oxide and carbon
dioxide gas. ∆
b. Al2(CO3)3 (s) Al2O CO2(g) 3

13. #11 Write and balance equations for the fol-
lowing reactions:
Solid magnesium reacts with aqueous
silver nitrate to form silver and aqueous
magnesium
c. Mg(s) + AgNO3(aq) Ag(s) + Mg(NO3)2(s) 2 2

14. b. Fe2O3 (s) + H2(g) Fe(s) + H2O(g)
#12 Write and balance equations for the fol-
lowing reactions:
a. SO2(s) O2(g) SO3(s) 2 2
b. Fe2O3 (s) + H2(g) Fe(s) H2O(g) 3 2 3
c. P(s) O2(g) P4O10(s) 4 5
d. Al(s) N2(g) AlN(s) 2 2