Balancing Chemical Equations

Since mass is neither created nor destroyed in a chemical reaction, a chemical equation must have the same number of atoms of each type of element as reactancts and products.

Steps in Balancing Equations

Ag + H₂S Ag₂S + H₂

1. Count the number of each type of atom in the reactants and products
2. Make a tally chart to keep a record of this count

   Element	Reactant	Products
   Ag	1	2
   H	2	2
   S	1	1

3. Determine the element(s) out of balance and use coefficients to balance
   
   Do not change (or add) subscripts!!
   
   • In our example, you would place a 2 in front of the Ag in the reactants because 2 x Ag = two atoms of silver
     2 Ag + H₂S Ag₂S + H₂
4. Recount the atoms on both sides of the equation and fix tally chart.

   Element	Reactant	Products
   Ag	12	2
   H	2	2
   S	1	1

5. Repeat the above steps until all elements are in balance

Try these.

1. CaCO₃ + HCl CO₂ + CaCl₂ + H₂O
2. Fe + O₂ Fe₂O₃
3. Li + H₂O LiOH + H₂
4. KClO₃ KCl + O₂
5. Li + FeBr₂ LiBr + Fe

Check your answers

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