Balancing Equations

1
Balancing Equations

• Conservation of mass

2
What Are Chemical Equations?
- Describing Chemical Reactions

• chemical formulas and other symbols instead of
  words to summarize a reaction.
• Reactants substances that begin a reaction
• Products substances formed in a reaction

3
Conservation of Mass
- Describing Chemical Reactions

• in a chemical reaction, the total mass of the
  reactants must equal the total mass of the
  products

4
Balancing Chemical Equations
- Describing Chemical Reactions

• a chemical equation must show the same number of
  each type of atom on both sides of the equation.

5
Examples

• HCl Zn ? ZnCl2 H2
• Are the same numbers of atoms on both sides?
• Which side has less of an element?
• 2HCl Zn ? ZnCl2 H2

6
Balancing Equations Activity
- Describing Chemical Reactions

• Go to my website http//admin.bhbl.neric.org/klo
  ng to practice equations.

7
Energy and Reactions
- Controlling Chemical Reactions

• All chemical reactions need a certain amount of
  activation energy to get things started.

8
Rates of Chemical Reactions
- Controlling Chemical Reactions

• The cells in your body (as in all living things)
  contain biological catalysts called enzymes. At
  the end of a reaction, an enzyme molecule is
  unchanged.

9
What increases reaction rate?(how fast a
reaction will happen)
- Controlling Chemical Reactions
Causes
Increase in surface area
Effect
Increase in temperature
Increased rate of reaction
Increase in concentration of reactants (NOT add
more of the chemical!!!!)
Use of a catalyst
Law of conservation of mass with Brainpop