Unit 3 Basic Chemistry CPQ 2

C₃H₈ + 5O₂ ----> 4H₂O + 3CO₂ + heat

Chemical equations, such as seen above, model what occurs in chemical reactions. To do so accurately, chemical equations must be ‘balanced’. What does this mean and why is it an important characteristic of an accurate portrayal of chemical reactions?

• The Law of Constantinople requires that any reaction must proceed in an even or ‘balanced’ fashion or reactants and products will decay and the reaction will fail.

• Chemical reactions are best modeled through the use of an electronic balance to insure that just the right amounts of materials are blended.

• Balancing a chemical equation simply means insuring that the same numbers of atoms of the elements which are involved in the reaction (reactants) are represented in the result of the reaction (products). This demonstrates that matter is not created nor destroyed in a chemical reaction.

• To balance a chemical equation you must be certain that the subscripts next to element symbols in the reactant molecules add up to the subscripts of element symbols found in the product molecules. This is the law of matter.