1. Chemical Equations & Reactions

2. Indications of a Chemical Reaction
Evolution of heat/light
Exothermic and Endothermic
Production of a gas
Formation of a precipitate
Solid that is produced and separates
Color change
Fireworks video (6 min)
Overview of chemical reactions (2 min)

3. Factors Influencing Rate of Reaction
Nature of reactants
Surface area
Temperature
Concentration
Catalyst
Increased surface area

4. Chemical Equations
Chemical Equation = represents, with symbols and formulas, the identities and relative amounts of reactants and products
Reactants (R) – left of arrow
Products (P) – right of arrow

5. Symbols used in Equations
 - yields
 - reversible reaction
 - gaseous product
 – solid product
(g) – gaseous reactant or product
(s) – solid reactant or product
(l) – liquid reactant or product
(aq) – aqueous (dissolved in water)

6. Writing Chemical Equations
Must have correct formulas for each R and P
Don’t forget diatomic elements Br2, I2, N2, Cl2, H2, O2, F2
Law of Conservation of Mass must be satisfied
Balance the equation with coefficients

7. Translating Equations
Write the balanced chemical equations:
1. Calcium phosphate and iron(II) oxide are produced from the reaction of calcium oxide and iron(II) phosphate.
2. The reaction of zinc with aqueous hydrochloric acid produces a solution of zinc chloride and hydrogen gas.

8. Types of Chemical Reactions
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion

9. Synthesis Reaction Two or more substances combine to form one product
EX: Calcium + oxygen → ??
EX: Barium + chlorine → ??

10. Decomposition Reaction
Single compound breaks down into several simpler substances
There are 4 types of decomposition reactions

11. Binary Decomposition Metal oxide → metal + oxygen gas
EX: Zinc oxide → ??
Decomposition of nitrogen triiodide

12. Metal Carbonate Decomposition
Metal carbonate → metal oxide + carbon dioxide
EX: Strontium carbonate → ??

13. Metal Chlorate Decomposition
Metal chlorate → metal chloride and oxygen gas
EX: Iron (III) chlorate → ??
EX: Potassium hypochlorite → ??

14. Metal Hydroxide Decomposition
Metal hydroxide → metal oxide + water
EX: Calcium hydroxide → ??

15. Single Replacement One metal replaces a metal in another compound OR
One nonmetal replaces a nonmetal in another compound
EX: Copper + silver nitrate  ??
EX: Calcium chloride + fluorine gas  ??
Thermite

16. Will a SR reaction always occur??
Check the Activity Series
The more reactive element will make a bond. If the more reactive element is already bonded, write NR for no reaction.
EX: Silver + copper (I) nitrate  ??
Reactivity of Alkali Metals

17. Double Replacement
Ions of 2 reactants exchange places in an aqueous solution to form new products
EX:
Zinc oxalate + ammonium phosphate → ??

18. More on Double Replacement
Some of the products may exist as ions in an aqueous solution, while others may exist as a solid
Soluble Cmpd (aq) = Exists as ions in solution
Insoluble Cmpd (s) = Exists as a solid in solution

19. Soluble or Insoluble??
Check the solubility chart or rules on reference sheet
Be sure to indicate which product is soluble and which is insoluble!!!!!
Double Replacement - Production of Precipitate

20. Examples of Solubility
Are these compounds soluble or insoluble?
K2SO4
AgCl
BaSO4
CaS
K3PO4
MgCO3

21. Net Ionic Equations
Includes only the compounds and ions that are chemically changed
Step 1: Write the products in words. Translate into a balanced equation – including states (use solubility rules)
Step 2: Write the overall ionic equation – cancel spectator ions.
Step 3: Write the net ionic equation – including states

22. Example
Zinc nitrate + ammonium sulfide → ??

23. Combustion
A substance reacts with oxygen to produce lots of energy, usually in the form of heat and light

24. Complete Combustion C_H_ + O2  H2O + CO2 + energy
EX: Propane + oxygen gas → ??
Combustion Video (5 min)
Origin of Combustion Engine Part 1(2 min)
Origin of Combustion Engine Part 2 (3 min)
Hindenburg Disaster (4 min)

25. Incomplete Combustion
C_H_ + O2  H2O + CO2 + C + CO + E
Dangerous product = CO