High School Chemistry  ·  Practice by Skill

Balancing Equations Practice Problems

A balanced chemical equation shows that atoms are never created or destroyed, only rearranged. Balancing is a skill you build with repetition, and it feeds straight into the quantity work in later units. Practice below covers balancing, identifying reaction types, and spotting precipitates and spectator ions.

What you’ll practice

  • Balancing equations: choose coefficients so every element has the same count on both sides.
  • Reaction types: classify reactions as synthesis, decomposition, single replacement, double replacement, or combustion.
  • Predicting products: work out what forms from the reactants and write it correctly.
  • Precipitates and spectator ions: use solubility rules to find the solid and the ions that do not take part.

Learn the method first →

A quick example: balancing combustion of propane

Balance the carbon first, then hydrogen, and leave oxygen for last because it appears in two products.

3 carbons on the left means 3 CO2. 8 hydrogens means 4 H2O. Now the products hold 6 + 4 = 10 oxygen atoms, which needs 5 O2.

C3H8+5 O2→3 CO2+4 H2O

Check each side: 3 C, 8 H, and 10 O. The equation is balanced.

3 free balancing equations problems

Give each one a real try before you open the solution. Your answer is checked as soon as you submit it, and the worked solution shows every step so you can see exactly where a setup went wrong.

#1Balancing Equations
Balance the equation: _Fe + _O2 → _Fe2O3. What is the coefficient in front of Fe in the balanced equation?
#2Reaction Notation
In a chemical equation, what does the arrow (→) between reactants and products represent?
#3Precipitation Reaction
Two solutions are mixed: Ba(NO3)2(aq) and Na2SO4(aq). Which product is a precipitate, and which ions are spectators?

Questions you might have about balancing equations

What does it mean to balance a chemical equation?
It means adjusting the coefficients so each element has the same number of atoms on both sides of the arrow. That reflects the law of conservation of mass.
What are the steps to balance an equation?
List the atoms on each side, balance elements that appear in only one reactant and one product first, and save oxygen and hydrogen for last. Change only coefficients, never subscripts, and recount every element at the end.
What are the five main types of chemical reactions?
Synthesis (two or more substances combine), decomposition (one substance splits), single replacement (one element swaps in for another), double replacement (two compounds swap partners), and combustion (a substance burns in oxygen).
How do I know if a precipitate forms?
Swap the partners in a double replacement reaction and check the new compounds against the solubility rules. If one of them is insoluble, it is the precipitate and the ions that stay dissolved are spectator ions.
High School Chemistry · Balancing Equations Practice Problems