1. Introduction to Chemical Reactions

2. Products-___________
Chemical Reaction-process that changes one set of chemicals into another set of chemicals.
A. Components
1. Reactants-substances that change
2. Products-new substance formed
-Example #1
CO2 + H20-->H2CO3
Reactants-__________
Products-___________
(Carbon dioxide reacts with water to produce carbonic acid. This keeps the body in homeostasis.)

3. Examples Continued Reactant- Product- # 2.
Mg + 2 H2O ---> 2 Mg(OH)2 +H2
What are the parts of the equation?
Reactant-
Magnesium (Mg), Hydrogen (H) and Oxygen (O)
Product-
Magnesium Hydroxide (MgOH2) and Hydrogen gas (H2)
What is the evidence for the reaction?
Formation of a gas!

4. Examples Continued Products- Reactants- # 3.
2 Mg + O2  2 MgO
What are the parts of the equation?
Products-
Magnesium (Mg) and Oxygen (O)
Reactants-
Magnesium Oxide (MgO)
What is the evidence for the reaction?
Formation of a precipitate!

5. B. Energy in Reactions-energy is released or absorbed any time chemical bonds are broken.
Types
A. Endothermic-energy is absorbed
(The energy required to break bonds is greater than the energy released when the new bonds are formed; additional energy needed is absorbed from the surroundings, thus causing the reaction to cool).
Example:
CH3COOH + NaHCO3 + thermal energyH2O + CO2 +CH3COONa
Vinegar+ Baking Soda Water +Carbon dioxide + Sodium Acetate
Evidence: loss of heat

6. B. Exothermic-energy is released
(the energy required to break bonds is less than the energy required to form new bonds, thus causing the reaction to produce heat).
Example: 2 Mg + O2  2 MgO
Magnesium + Oxygen  Magnesium Oxide
Evidence: Light is produced