1. Topic 4.0 Chemical Reactions

2. Program of Studies Factors affecting reaction rates
Conservation of mass
Endothermic and exothermic reactions
Reactants and Products

3. POS cont’d
observing heat generated or absorbed in chemical reactions, and identifying examples of exothermic and endothermic reactions
Identifying conditions that affect rates of reactions (e.g., investigate and describe how factors such as heat, concentration, surface area and electrical energy can affect a chemical reaction)

4. Factors affecting reaction rates
Heat (Temperature)
Heat increases collisions between particles
Concentration
More atoms available to react
Surface area
More area available for reaction
Breaking material into smaller pieces
Electrical energy (electrolysis)
Catalyst (enzymes)
Teacher demo pg 167

5. Conservation of mass
The amount of products always equals the mass of reactants
Mass is neither created or destroyed, but may be converted to other forms (energy)

6. Ex pg 163 *Remember: mass is measured in grams (g) Mg + S -> MgS
24 g + 32 g -> ?
Total mass = 56 g

7. Endothermic and Exothermic reactions
Demos
Endothermic
Cold Pack
Exothermic
Whoosh Bottle
CaCl2 + NaHCO3 + bromothymol blue (in ziploc)
Lab pg 164 sia
Hand warmers

8. Endothermic Thermic-heat Endo-Takes in energy Energy is being absorbed
(so the material feels cool)

9. Exothermic Thermic-heat Exo- Releases energy Energy is being generated
(so the material feels hot)

10. Reactants and Products
Reactants: substances that are going to chemically “react”
Products: new substances produced in a chemical reaction
Ex: hydrogen + oxygen -> water
reactant reactant 2 -> product

11. The burning of fuel C3H8 + O2 -> CO2 + H2O +energy
Identify the type of reaction
Identify whether the reaction is endothermic or exothermic
Identify the products and reactants
Name each compound (C3H8 is propane)

12. The burning of fuel C3H8 + O2 -> CO2 + H2O +energy
Identify the type of reaction
Combustion (O2)
Identify whether the reaction is endothermic or exothermic
Releases energy- exothermic
Identify the products and reactants
REACTANTS: C3H8 + O2
PRODUCTS: CO2 + H2O +energy
Name each compound (C3H8 is propane)
propane + oxygen -> carbon dioxide + water + energy

13. The corrosion of iron iron + oxygen -> iron(II)oxide
Identify the type of reaction
Identify the products and reactants
Write the formula for each compound

14. The corrosion of iron iron + oxygen -> iron(II)oxide
Identify the type of reaction
oxidation (rusting)
Formation of a metal “oxide”
Identify the products and reactants
REACTANTS: iron + oxygen
PRODUCTS: iron(II)oxide
Write the formula for each compound
Fe + O2 -> FeO

15. The reaction: zinc + copper(II)sulfate → zinc sulfate + copper
Identify the type of reaction
Identify the products and reactants
Write the formula for each compound

16. The reaction: zinc + copper(II)sulfate → zinc sulfate + copper
Identify the type of reaction
Single replacement
Identify the products and reactants
REACTANTS: zinc + copper(II)sulfate
PRODUCTS: zinc sulfate + copper
Write the formula for each compound
Zn + CuSO4 → ZnSO4 + Cu

17. The reaction: zinc + copper(II)sulfate → zinc sulfate + copper
If:
mZn= 12 g
mCuSO4= 28 g
mZnSO4= 14 g
Then
mCu= ?

18. The reaction: zinc + copper(II)sulfate → zinc sulfate + copper
12 g + 28 g -> 14 g + ? g
40 g -> 14 g + 26 g
Then mCu=26 g

19. Assignments
Journals
Vocab
Worksheets
Section 4.0 Q’s
Unit Review