Balancing Equations

Law of Conservation of Matter

A natural law describing the fact that matter is neither created nor destroyed in any process

Simply means that: The amount of matter that you start

with has to equal to the amount of matter that you end with

Important rules to follow 1. Make sure all compounds are correct.

Important in high school. (diatomics/polyatomics) 2. Go for the largest molecule, and pick the

front element of that molecule. 3. Place elements under the arrow and

amounts in same order underneath the reactants side and underneath the products side.

4. Leave Oxygen and Hydrogen last. **5 If one side must be an even number and

the other side has an odd number, then multiply the odd number with an even coefficient to make even.

___Mg + ___O2 __MgO

Go to the largest compoundList the elements and amount

___Mg + ___O2 __MgO

1 Mg 1

2 O 1

__2_Mg + ___O2 _2_MgO

__N2 + __H2 ____NH3

2 N 1 2 H 3

Go to largest moleculeBalance first element

__N2 + _3_H2 __2__NH3

___Na + ___Cl2 ____NaCl

_2_Na + ___Cl2 _2__NaCl

__Na + __H2O __NaOH + __H2

__Na + __H2O __NaOH + __H2

1 Na 1 1 O 1 2 H 3

_2_Na + _2_H2O _2_NaOH + __H2

__Ca + __H2O __Ca(OH)2

+__H2

__Ca + _2_H2O __Ca(OH)2

+__H2

Warmups # 1 and 2Try to balance this one.

Al2O3 Al + O2

# 2

BaO2 BaO + O2

#3

Fe + CuCl2 FeCl2 + Cu

#4

CuCl2 + H2S CuS + HCl

5.

P4 + H2 PH3

6.

O2 + Sb2S3 Sb2O4 + SO2

7.

PaI5 Pa + I2

8.

Hf + N2 Hf3N4

9.

C12H22O11 C + H2O

10.

Fe + O2 Fe3O4