BALANCING EQUATIONS HELP

When balancing equations

  • Write the correct chemical formula for each chemical species in the equation.
  • Change the co-efficients (whole numbers on the left of a chemical formula) so that,

 the number and type of atoms on the reactants (left) = the number and type of atoms on the products (right)

 

When this is achieved the chemical equation is balanced.

 

Determine the number of atoms for each element in the following equations

1. Sodium + oxygen sodium oxide

Unbalanced
Balanced

Na + O2 → Na2O

 Element Reactants Products Balanced

 Na

atoms

1
How many?
2
How many?

 O

atoms

2
How many?
1
How many?

 

Look for an uneven number of O atoms.

Double it.   ie. 2Na2O

Na + O2 → 2Na2O

 Element Reactants Products Balanced

 Na

atoms

1
How many?
4
How many?

 O

atoms

2
How many?
2
How many?

 

Finally, balance the number of Na atoms.

4Na + O2 → 2Na2O

 Element Reactants Products Balanced

 Na

atoms

4
How many?
4
How many?

 O

atoms

2
How many?
2
How many?

  

2. Sodium + chlorine sodium chloride

Unbalanced
Balanced

Na + Cl2 → NaCl

 Element Reactants Products Balanced

Na

atoms

1
How many?
1
How many?

Cl

atoms

2
How many?
1
How many?

2Na + Cl2 → 2NaCl

 Element Reactants Products Balanced

Na

atoms

2
How many?
2
How many?

Cl

atoms

2
How many?
2
How many?

 

3. Sodium + water sodium hydroxide + hydrogen

Unbalanced
Balanced

Na + H2O → NaOH + H2

 Element Reactants Products Balanced

Na

atoms

1
How many?
1
How many?

H

atoms

2
How many?
3
How many?

O

atoms

1
How many?
1
How many?

2Na + 2H2O → 2NaOH + H2

 Element Reactants Products Balanced

Na

atoms

2
How many?
2
How many?

H

atoms

4
How many?
4
How many?

O

atoms

2
How many?
2
How many?

 

4. Sodium + hydrogen sodium hydride

Unbalanced
Balanced

Na + H2 → NaH

 Element Reactants Products Balanced

Na

atoms

1
How many?
1
How many?

H

atoms

2
How many?
1
How many?

2Na + H2 → 2NaH

 Element Reactants Products Balanced

Na

atoms

2
How many?
2
How many?

H

atoms

2
How many?
2
How many?

 

5. Sodium + nitrogen sodium nitride

Unbalanced
Balanced

Na + N2 → Na3N

 Element Reactants Products Balanced

Na

atoms

1
How many?
3
How many?

N

atoms

2
How many?
1
How many?

6Na + N2 → 2Na3N

 Element Reactants Products Balanced

Na

atoms

6
How many?
6
How many?

N

atoms

2
How many?
2
How many?

 

 

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