Science, Tech, Math › Science Examples of 10 Balanced Chemical Equations See How To Write Balanced Equations Share Flipboard Email Print Jeffrey Coolidge/The Image Bank/Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated October 02, 2019 Writing balanced chemical equations is essential for chemistry class. Here are examples of balanced equations you can review or use for homework. Note that if you have "1" of something, it does not get a coefficient or subscript. The word equations for a few of these reactions have been provided, though most likely you'll be asked to provide only the standard chemical equations. Key Takeaways: Examples of Balanced Equations In chemistry, it's important to be able to recognize when equations are balanced, when they are not balanced, and how to balance them.A balanced equation contains the same number of each type of atoms on both the left and right sides of the reaction arrow.To write a balanced equation, the reactants go on the left side of the arrow, while the products go on the right side of the arrow.Coefficients (number in front of a chemical formula) indicate moles of a compound. Subscripts (numbers below an atom) indicate the number of atoms in a single molecule.To calculate the number of atoms, multiply the coefficient and the subscript. If the atom appears in more than one reactant or product, add together all the atoms on each side of the arrow.If there is only one mole or one atom, then the coefficient or subscript "1" is implied, but is not written.A balanced equation is reduced to the lowest whole number coefficients. So, if all the coefficients can be divided by 2 or 3, do this before finalizing the reaction. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 (balanced equation for photosynthesis)6 carbon dioxide + 6 water yields 1 glucose + 6 oxygen 2 AgI + Na2S → Ag2S + 2 NaI2 silver iodide + 1 sodium sulfide yields 1 silver sulfide + 2 sodium iodide Ba3N2 + 6 H2O → 3 Ba(OH)2 + 2 NH3 3 CaCl2 + 2 Na3PO4 → Ca3(PO4)2 + 6 NaCl 4 FeS + 7 O2 → 2 Fe2O3 + 4 SO2 PCl5 + 4 H2O → H3PO4 + 5 HCl 2 As + 6 NaOH → 2 Na3AsO3 + 3 H2 3 Hg(OH)2 + 2 H3PO4 → Hg3(PO4)2 + 6 H2O 12 HClO4 + P4O10 → 4 H3PO4 + 6 Cl2O7 8 CO + 17 H2 → C8H18 + 8 H2O 10 KClO3 + 3 P4 → 3 P4O10 + 10 KCl SnO2 + 2 H2 → Sn + 2 H2O 3 KOH + H3PO4 → K3PO4 + 3 H2O 2 KNO3 + H2CO3 → K2CO3 + 2 HNO3 Na3PO4 + 3 HCl → 3 NaCl + H3PO4 TiCl4 + 2 H2O → TiO2 + 4 HCl C2H6O + 3 O2 → 2 CO2 + 3 H2O 2 Fe + 6 HC2H3O2 → 2 Fe(C2H3O2)3 + 3 H2 4 NH3 + 5 O2 → 4 NO + 6 H2O B2Br6 + 6 HNO3 → 2 B(NO3)3 + 6 HBr 4 NH4OH + KAl(SO4)2·12H2O → Al(OH)3 + 2 (NH4)2SO4 + KOH + 12 H2O Check Equations to Make Sure They Are Balanced When you balance a chemical equation, it's always a good idea to check the final equation to make sure it works out. Perform the following check:Add up the numbers of each type of atom. The total number of atoms in a balanced equation will be the same on both sides of the equation. The Law of Conservation of Mass states the mass is the same before and after a chemical reaction.Make sure you accounted for all types of atoms. Elements present on one side of the equation need to be present on the other side of the equation.Make sure you can't factor out the coefficients. For example, if you could divide all of the coefficients on both sides of the equation by 2, then you may have a balanced equation, but not the simplest balanced equation. Sources James E. Brady; Frederick Senese; Neil D. Jespersen (2007). Chemistry: Matter and Its Changes. John Wiley & Sons. ISBN 9780470120941.Thorne, Lawrence R. (2010). "An Innovative Approach to Balancing Chemical-Reaction Equations: A Simplified Matrix-Inversion Technique for Determining the Matrix Null Space". Chem. Educator. 15: 304–308.