1. Unit: Chemical Reactions
Day 4 - Notes
Unit: Chemical Reactions
Types of Chemical Reactions: Synthesis and Decomposition
Upper left: Thermite reaction, Fe2O3 + Al => 2Fe +2Al2O3 + HEAT!!!
Upper right: potassium in water, K + H2O => KOH + H2 + HEAT
Bottom right: potassium chlorate and sugar, C12H22O11 + 8KClO3 => 12CO2 + 11H2O + 8KCl + HEAT!!!
Bottom left: magnesium reacting with oxygen, Mg + O2 => MgO

2. After today you will be able to…
Identify synthesis and decomposition reactions
Predict the products in words for synthesis and decomposition reactions
heat Pt

3. Types of Chemical Reactions
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
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4. Element + Element  Compound
Predicting Products
Synthesis: Two elements combine to form a compound
Common form:
Element + Element  Compound
A + B  AB
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5. Examples of synthesis:
sodium + chlorine  magnesium + phosphorus  sulfur + aluminum 
(Metal)
(Non-metal)
(Metal)
(Non-metal)
sodium chloride
magnesium
phosphide
aluminum sulfide
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6. Compound  Element + Element
Predicting Products
2. Decomposition: A compound breaks down into elements and/or smaller compounds Common form:
Compound  Element + Element
AB  A + B
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7. Examples of decomposition:
potassium nitride 
potassium + nitrogen
Go back to the non-metal’s original ending.
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8. Examples of “special” decompositions:1.
Example of a metal chlorate decomposition:
barium chlorate 
metal chlorate  metal chloride + oxygen
(ClO3)-1
barium chloride + oxygen
Always a part of the product!
heat Pt

9. Examples of “special” decompositions:2.
Example of a metal carbonate decomposition:
potassium carbonate
metal carbonate  metal oxide + carbon dioxide
(CO3)-2
potassium oxide + carbon dioxide
Always a part of the product!
heat Pt

10. Examples of “special” decompositions:3.
Example of a metal hydroxide decomposition:
tin (IV) hydroxide
metal hydroxide  metal oxide + water
(OH)-1
tin(IV) oxide + water
Always a part of the product!
Don’t forget the Roman numeral!
heat Pt