1. Balancing Equations 08/15/12

2. 10.1 Reactions and Equations • The process by which the atoms of one substance are rearranged to form different substances is called a chemical reaction. Subscript Coefficient CH4 + 2 O2 CO2 + 2 H2O Reactant Product

3. Law of conservation of mass- that mass is neither created nor destroyed during a chemical reaction but is conserved. • We balance equations because it shows that the reactions obeys the law of conservation of mass.

4. Balancing Equations • Steps to balancing equations: • Draw a line to separate the reactants from the products • Count the atoms of the elements in the reactant. • Count the atoms of the elements in the product. • Change the coefficients (#’s in front) to make the number of atoms of each element equal on both sides of the equation.

5. Example __Al + ___Fe2O3 ___Fe + ___Al2O3

6. Example • ___Mg + ____N2 ___Mg3N2

7. Examples ___Cu(NO3)2 ___CuO + ___NO2 + ___ O2

8. Example ____C3H8 + ___ O2  ___ CO2 + ____H2O