2. 4 Types of chemical
reactions
-SYNTHESIS REACTION
-TWO OR MORE SUBSTANCES
COMBINE TO MAKE A MORE COMPLEX
SUBSTANCE
-example:
- 2H2 + O2 → 2H2O
Hint: End with fewer types
of molecules!

3. Decomposition Reaction:
-one substance is broken down into
two or more substances.
-The opposite of a synthesis
reaction!
-example:
2NaClO3 → 2NaCl + 3O2
Hint! End with higher
number of molecules

4. - Electrolysis (running electric
current through materials) is
a method used to cause
decomposition reactions to
obtain pure substances.

6. Single replacement reaction
-an uncombined element takes the place of
an element that is part of a compound.
- example:
Zn + 2HCl → H2 + ZnCl2

7. Zn + 2HCl → H2 + ZnCl2
Reactants
Products
Zn + H Cl

8. Double replacement
reaction:
-different atoms in two different
compounds replace each other
(two compounds react to form two
new compounds).
-examples:
2K + P
I b(NO3) 2 → 2K 3 + P 2
NO bI

10. Combustion Reactions
• Combine a fuel with oxygen to produce
water and carbon dioxide
• 3 parts of this rxn are always the same!
• Only the fuel will change
• C2H6 + O2  H2O + CO2
• CH4 + O2  H2O + CO2
• C3H8 + O2  H2O + CO2