Balancing Chemical Equations Chapter 8-1

Balancing Chemical Equations Law of Conservation of Matter Atoms are not created nor destroyed during a chemical reaction. Scientists know that thee must be the same number of atoms on each side of the chemical equation. The chemical equation must be balanced so that it conforms to the Law of Conservation of Matter.

Steps to Balance a Chemical Equation Balanced Chemical Equation A balanced chemical equation is an equation that shows that the number of atoms in the reactant side equal to the number of atoms in the product side. Steps to Balance a Chemical Equation Step-by-Step Example Problem Step 1: Determine the number of atoms for each element. Mg + O2 MgO 1 = Mg = 1 2 = O = 1

Since the O atoms are not equal, we’ll target these first Step 2: Pick an element that is not equal on both sides of the equation. Mg + O2 MgO 1 = Mg = 1 2 = O = 1

Adding a 2 in front of MgO will change the number of atoms on the product side. Step 3: Add a coefficient in front of the formula with that element and adjust your counts. Mg + O2 2 MgO 1 = Mg = 1 2 2 = O = 1 2

Now we increase the Mg atoms on the reactant side Now we increase the Mg atoms on the reactant side. By adding a 2 in front of Mg, the chemical equation is balanced. Step 4: Continue adding coefficients to get the same number of atoms of each element on each side. 2 Mg + O2 2 MgO 1 = Mg = 1 2 2 = O = 1 2 Final chemical equation: 2 Mg + O2 2 MgO