2. Six Types of Reactions Synthesis Synthesis Decomposition Decomposition Single Replacement Single Replacement Double Replacement Double Replacement Combustion Combustion Acid-Base (We will talk about this later.) Acid-Base (We will talk about this later.)

3. Synthesis reactions Two substances combine and form one compound. Two substances combine and form one compound. Form: A + B  AB Form: A + B  AB Explosion of the Hindenburg Explosion of the Hindenburg Example: 2H 2 + O 2  2H 2 O Example: 2H 2 + O 2  2H 2 O

4. Synthesis Reactions

5. Decomposition Reactions One compound breaks down into two or more substances Form: AB  A + B Example: 2H 2 O → 2H 2 + O 2

6. Decomposition Car air bags -Sodium azide is electrically stimluated to decompose into nitrogen gas and sodium nitrate 2NaN 3 → Na 3 N + 4N 2 Many decomposition reactions involve the fast release of large quantities of energy. Many decomposition reactions involve the fast release of large quantities of energy.

7. Decomposition Reactions

8. Single Replacement Reactions One element replaces another in a compound. One element replaces another in a compound. Form: A + BC  AC + B Form: A + BC  AC + B Example: Example: Mg + 2H 2 O → Mg(OH) 2 + H 2

9. Single Replacement Reactions

10. Double Replacement Reactions Two elements switch places to form 2 new compounds Two elements switch places to form 2 new compounds Form: AB + CD  AD + CB Form: AB + CD  AD + CB Ex: HCl + NaOH  NaCl + H 2 O Ex: HCl + NaOH  NaCl + H 2 O

11. Combustion Reactions Oxygen reacts with another element to make water and CO 2. Oxygen reacts with another element to make water and CO 2. Releases energy as heat and light. Releases energy as heat and light. Some combustion reactions can be synthesis reactions. Some combustion reactions can be synthesis reactions.

12. Combustion Reactions Form: X + O 2  CO 2 + H 2 O C 10 H 8 + 12O 2  10CO 2 + 4H 2 0 Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C 8 H 18 )

13. SynthesisDecomposition Single replacement Double replacement _______ Pb(NO 3 ) 2 + 2NaI → PbI 2 + 2Na(NO 3 ) _______NH 3 + H 2 O → (NH 4 )(OH) _______CaF 2 + H 2 (SO 4 ) → Ca(SO 4 ) + 2 HF _______N 2 + 3H 2 → 2NH 3 _______MgI 2 + Br 2 → MgBr 2 + I 2 _______2H 2 O → 2H 2 + O 2 _______C 4 H 10 _______C 4 H 10 + O 2 -> CO 2 + H 2 O What type of Reaction?