Balancing Chemical Equations

Basic Steps for balancing chemical equations

1. Start with a correct (unbalanced) formula equation. If the formulas are not correct, then you won’t be able to proceed!

NaOH + H2SO4 Na2SO4 + H2O

Basic Steps for balancing chemical equations

2. Draw a box around each chemical formula. This is an error-proofing step so that you don’t accidentally change a subscript, which is a MAJOR No-No! Do not EVER change anything inside a box!!!!!!!

NaOH + H2SO4 Na2SO4 + H2O

Basic Steps for balancing chemical equations

3. Create an element inventory to track how many atoms of each element are on each side of the equation.

NaOH + H2SO4 Na2SO4 + H2O

Reactants Element Products

1 Na 2

5 O 5

3 H 2

1 S 1

Basic Steps for balancing chemical equations

3. Add coefficients in front of each box until the inventory for each element is the same for reactants and products.

NaOH + H2SO4 Na2SO4 + H2O

Reactants Element Products

1 Na 2

5 O 5

3 H 2

1 S 1

2

264

2

46

Basic Steps for balancing chemical equations

4. Count each atom again to make sure you have the same number of each type of element on both sides!!!

NaOH + H2SO4 Na2SO4 + H2O

Reactants Element Products

1 Na 2

5 O 5

3 H 2

1 S 1

2

264

2

46

MINOH Method

In general, you want to start with the element(s) that only appear in one compound on each side of the reaction.

If a polyatomic ion appears in the reactants and also as the same polyatomic ion in the products, you can treat it as a single unit in the element inventory.

Leave oxygen and hydrogen for last (usually).

MINOH Method

Balance Metals first (M) Balance polyatomic ions that don’t change

from the reactant to the product side next. Balance them as a single unit. (I)

Balance non-metals next (N) Leave oxygen and hydrogen for last (O H)

This should work most of the time. Except when it doesn’t.

Final Word of Advice

Count everything at the end to make sure you have balanced the equation correctly!!

If you get stuck, start over. A fresh perspective usually helps!

Examples to try together

NaCl + BeF2 NaF + BeCl2 FeCl3 + Be3(PO4)2 BeCl2 + FePO4