The number of atoms of each element
on the reactant side of the equation
must equal the number of atoms of
each element on the product side.
Step #1 – Write the skeleton equation (if necessary) using
chemical formulas.
Step #2
#2 – Balance the atoms using coefficients.
coefficients
Make sure to use the lowest common multiple.
Never change the subscript numbers in a chemical
formula.
If there are identical polyatomic ions on both sides, treat
them as if they are a single atom.
Step #3 – Check your balancing. Use a list or chart to keep
count.
Balancing equations takes time and practice! Do not rush!
1. ___ N2(g) + ___ H2(g) → ___ NH3(g)
2. ___ CaC2(s) + ___ H2O(l) → ___ Ca(OH)2(s) + ___ C2H2(g)
3. ___ SiCl4(s) + ___ H2O(l) → ___ SiO2(s) + ___ HCl(aq)
4. ___H3PO4(aq) + ___CaSO4(s) →
___Ca3(PO4)2(s) + ___H2SO4(aq)
Balancing Chemical Equations – Worksheet 1
◦ Use a separate sheet of paper to show the work!
Complete Check and Reflect on page 90:
7all, 8all, 9ace (answers are in the textbook)
Chemical Equations Quiz (writing and balancing) –
Next Class
Pre-read A3.3 Five Common Types of Chemical
Reactions (pages 91-105)