1. Reaction Types

2. Combination (Synthesis) Reactions Two or more substances combine to form a new compound. A + X  AX  Reaction of elements with oxygen and sulfur  Reactions of metals with Halogens  Synthesis Reactions with Oxides  There are others not covered here!

3. Decomposition Reactions A single compound undergoes a reaction that produces two or more simpler substances Decomposition of: Binary compounds H 2 O( l )  2H 2 (g) + O 2 (g) Metal carbonates CaCO 3 (s)  CaO(s) + CO 2 (g) Metal hydroxides Ca(OH) 2 (s)  CaO(s) + H 2 O(g) Metal chlorates 2KClO 3 (s)  2KCl(s) + 3O 2 (g) Oxyacids H 2 CO 3 (aq)  CO 2 (g) + H 2 O( l ) AX  A + X

4. Single Replacement Reactions Replacement of:  Metals by another metal  Hydrogen in water by a metal  Hydrogen in an acid by a metal  Halogens by more active halogens A + BX  AX + B BX + Y  BY + X

5. The Activity Series of the Metals Lithium Potassium Calcium Sodium Magnesium Aluminum Zinc Chromium Iron Nickel Lead Hydrogen Bismuth Copper Mercury Silver Platinum Gold  Metals can replace other metals provided that they are above the metal that they are trying to replace  Metals above hydrogen can replace hydrogen in acids.  Metals from sodium upward can replace hydrogen in water

6. The Activity Series of the Halogens Fluorine Chlorine Bromine Iodine Halogens can replace other halogens in compounds, provided that they are above the halogen that they are trying to replace. 2NaCl(s) + F 2 (g)  2NaF(s) + Cl 2 (g) MgCl 2 (s) + Br 2 (g)  ??? No Reaction ???

7. Double Replacement Reactions The ions of two compounds exchange places in an aqueous solution to form two new compounds. AX + BY  AY + BX precipitateinsoluble gas molecular compound One of the compounds formed is usually a precipitate, an insoluble gas that bubbles out of solution, or a molecular compound, usually water.

8. Combustion Reactions A substance combines with oxygen, releasing a large amount of energy in the form of light and heat. Reactive elements combine with oxygen P 4 (s) + 5O 2 (g)  P 4 O 10 (s) (This is also a synthesis reaction) The burning of natural gas, wood, gasoline C 3 H 8 (g) + 5O 2 (g)  3CO 2 (g) + 4H 2 O(g)

9. neutralization A type of double replacement reaction Neutralization Acids are compounds that dissolve in water to produce solutions containing hydronium ions, H3O+ (aq), and bases dissolve in water to produce hydroxide ions, HO- (aq). When an acidic solution and a basic solution are mixed, hydroxide ions react with hydronium ions to produce water molecules: H3O+ (aq) + HO- (aq)  2 H2O H+ (aq) + HO- (aq)  H2O

10. neutralization This chemical process is called neutralization. What happens to the other ions that were present in the original solutions? Nothing! They are still separately solvated and moving independently, unaffected by the reaction going on around them. Let's look at the reaction between hydrochloric acid and sodium hydroxide: HCl (g)  H+ (aq) + Cl- (aq)

11. Reactions with hydrocarbons Reactions involving combustion of hydrocarbons (H and C) do not fit these 4 types Ex. Hydrocarbon + oxygen  carbon dioxide + water