Types of Chemical Reactions Synthesis Combination reaction A

Types of Chemical Reactions Synthesis (Combination) reaction A + B AB AB A + B Decomposition reaction Single-replacement reaction use activity series to predict Double-replacement reaction A + BC AC + B element compound element AB + CD AD + CB compound Combustion reaction (of a hydrocarbon) compound CH + O 2 CO 2 + H 2 O

Chemical Equations

Synthesis Reaction Direct combination reaction (Synthesis) 2 Na + Na Cl 2 Cl Cl 2 Na. Cl Na General form: A element or compound + B element or compound AB compound

Synthesis Reaction Direct combination reaction (Synthesis) 2 Na + Cl 2 Na. Cl Cl Na+ Cl - Cl Cl - Na+ Na General form: A element or compound + B element or compound AB compound

Synthesis Reactions Photosynthesis 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + Formation of water 2 H 2 + O 2 2 H 2 O Formation of salt 2 Na + Cl 2 2 Na. Cl General Form A + B AB 6 O 2

Decomposition Reaction Decomposition reaction 2 H 2 O 2 H 2 + O 2 H O H + H O H General form: AB compound A + B two or more elements or compounds

Decomposition Reactions Hydrogen Peroxide 2 H 2 O 2 2 H 2 O + 2 H 2 + O 2 Electrolysis of water 2 H 2 O electricity O 2 Nitrogen triiodide 2 NI 3 N 2 + 3 I 2 General Form AB A + B

Single and Double Replacement Reactions Single-replacement reaction Mg + Cu. SO 4 General form: A + BC Mg. SO 4 AC + + Cu B Double-replacement reaction Ca. CO 3 + General form: AB + 2 HCl Ca. Cl 2 + H 2 CO 3 CD AD + CB

Printable Version of Activity Series Element Reactivity Ca Foiled again – Aluminum loses to Calcium Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H 2 Cu Hg Ag Pt Au Halogen Reactivity F 2 Cl 2 Br 2 I 2

Single-Replacement Reactions Activity Series “Magic blue-earth” Fe + Cu. Cl 2 Fe. Cl 2 + Cu Can Fe replace Cu? Yes Zinc in Sodium nitrate Zn + Na. NO 3 NR Can Zn replace Na? No Mg. Cl 2 + Can Br replace Cl? Br 2 Mg. Br 2 + Kinda General Form A + BC AC + B Cl 2 Li Rb K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb H 2 Cu Hg Ag Pt Au F 2 Cl 2 Br 2 I 2

Predict if these reactions will occur 3 Mg + 2 Al. Cl 3 2 Al + 3 Mg. Cl 2 Can magnesium replace aluminum? YES, magnesium is more reactive than aluminum. Activity Series Al + Mg. Cl 2 No reaction Can aluminum replace magnesium? NO, aluminum is less reactive than magnesium. Activity Series Mg. Cl 2 + Al Therefore, no reaction will occur. No reaction Order of reactants DOES NOT determine how they react. The question we must ask is can the single element replace its counterpart? metal replaces metal or nonmetal replaces nonmetal.

Double Replacement Reaction K 2 CO 3 (aq) Potassium carbonate + Ba. Cl 2 (aq) Barium chloride 2 KCl (aq) Potassium chloride + Ba. CO 3 (s) Barium carbonate

Formation of a solid: Ag. Cl Ag. NO 3(aq) + KCl(aq) KNO 3 (aq) + Ag. Cl(s)

lead (II) chloride + potassium iodide K 1+ Pb 2+ Cl 1 Pb. Cl 2 + I 1 - KI Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. potassium chloride + lead (II) iodide Pb 2+ Cl 1 KCl (aq) K 1+ + I 1 - Pb. I 2 (ppt)

Solubility Rules 1. Most nitrates are soluble. 2. Most salts containing Group I ion and ammonium ion, NH 4+, are soluble. 3. 4. Most chloride, bromide, and iodide salts are soluble, except Ag+, Pb 2+ and Hg 22+. 4. Most sulfate salts are soluble, except Ba. SO 4, Pb. SO 4, Hg 2 SO 4, and Ca. SO 4. 5. 6. Most hydroxides except Group 1 and Ba(OH)2, Sr(OH)2, and Ca(OH)2 are only slightly soluble. 6. Most sulfides, carbonates, chromates, and phosphates are only slightly soluble. Ohn-Sabatello, Morlan, Knoespel, Fast Track to a 5 Preparing for the AP Chemistry Examination 2006, page 91

Combustion Reactions • A substance combines with oxygen and produces a combination of water and carbon dioxide. Usually involves hydrocarbons Cx. Hy + O 2 CO 2 + H 2 O C 3 H 8 + 5 O 2 3 CO 2 + 4 H 2 O