Balancing Act
Name_______________
Atoms are not __created___ or ________destroyed___________ during a chemical reaction.
Scientists know that there must be the ___same__ number of atoms on each ___side______ of the
___reaction___. To balance the chemical equation, you must add ____coefficients_____ in front of the
chemical formulas in the equation. You cannot ___add__ or ___remove____ subscripts.
1)
2)
3)
4)
Determine number of atoms for each element
Pick an element that is not equal on both sides of the equation.
Add coefficients in front of the element and adjust your counts.
Continue adding coefficients until you get the same number of elements on each side.
Example:
2
Mg
 2
+
O2
MgO
Mg =
2
Mg = 2
O=
2
O=2
Try these:
2
Ca
N2
2
2
Cu2O
H2O2
 2
+
O2
Ca =
2
Ca = 2
O=
2
O=2
+ 3
H2
 2
CaO
NH3
N=2
N=2
H=6
H=6
 4
+
C
Cu =
4
Cu = 4
O=
2
O=2
C=
1
C=1
 2
H2O
H=
4
H=4
O=
4
O=4
+
Cu
O2
+
CO2
Balancing Act Practice
Balance each equation. Be sure to show work. Remember you cannot add subscripts of place
coefficients in the middle of a chemical formula.
1.
2 Na
2.
Mg = 1
Mg = 1
F=2
F=2
+
H=2
H=2
Cl = 2
Cl = 2
+

2 KI
2 KCl +
Cl = 2
Cl = 2
K=2
K=2
I=2
I= 2
2 Na
+
Na = 2
Cl = 2
Cl = 2
+
O2

Na = 4
O=2
O=2
2 HCl

H2
Na = 2
Na = 2
Cl = 2
Cl = 2
H=2
H=2
2K
+
Cl2
H2
I2
2 Na2O
Na = 4
+
Mg
Cl2
Na = 2
2 Na
7.
MgCl2 +
Mg = 1
4 Na
6.

2 HCl
Mg = 1
2 NaCl 
5.
2 NaF +
Na = 2
Cl2
4.

MgF2
Na = 2
Mg
3.
+

+
2 NaCl
2 KCl
K=2
K=2
Cl = 2
Cl = 2
Challenge: This one is tough
2 C2H6
+
7 O2

4 CO2 +
C=4
C=4
H = 12
H = 12
O = 14
O = 14
6 H2O