How to write and Balance Equations

Step 1 Read the description of the chemical reaction. What are the reactants, the products, and their states? Write the appropriate formulas.

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Step 2 Write the unbalanced equation that summarizes the information from step 1. Be sure that that you check the charges of each of the ions so that the correct subscripts are placed in the formulas. Again if you need help on writing formulas click on the above link.

Step 3 Balance the equation by inspection, starting with the most complicated molecule. Proceed element by element to determine what coefficients are necessary so that the same number of each type of atom appears on both the reactant side and the product side. Do not change the formulas at this point. Remember that the charge of the cations and anion in the formulas must equal zero. If you change a formula in order to balance the equation the formula well then be incorrect.

Step 4 Check to see that coefficients used give the same number of each type of atom on both sides of the arrow. (Note that an “atom” may be present in an element, compound, or ion.) Also check to see that the coefficients used are the smallest integers that give the balanced equation. This can be done by determining whether all coefficients can be divided by the same integer to give a set of smaller integer coefficients.

For example 4H₂ + 2O₂ ® 4H₂O can be reduced to 2H₂ + O₂ ® 2H₂O .