Unit 7 Chemical Reactions Types of Reactions

Type of Reactions Chemical reactions are classified into five general types Synthesis (also called combination or addition) Decomposition Single Replacement (also called single displacement) Double Replacement(also called double displacement) Combustion

Synthesis (Combination) Two or more elements or simple compounds combine to form (synthesize) one product A + B AB 2Mg + O2 2MgO 2Na + Cl2 2NaCl SO3 + H2O H2SO4 When two elements combine in synthesis, the product is a compound made of their respective ions.

Combination (Synthesis) YouTube - Reaction of Sodium & Chlorine (with subtitles)

Synthesis (practice) Predict the products. Write and balance the following synthesis reaction equations. Sodium metal reacts with chlorine gas Na(s) + Cl2(g)  Solid Magnesium reacts with fluorine gas Mg(s) + F2(g)  Aluminum metal reacts with fluorine gas Al(s) + F2(g) 

Combination (Synthesis) Practice Predict the products. Write and balance the following synthesis reaction equations. Sodium metal reacts with chlorine gas 2 Na(s) + Cl2(g)  2 NaCl Solid Magnesium reacts with fluorine gas Mg(s) + F2(g)  MgF2 Aluminum metal reacts with fluorine gas 2Al(s) + 3 F2(g)  2AlF3

Decomposition AB A + B 2HgO 2Hg + O2 2KClO3 2KCl + 3 O2 One substance is broken down (split) into two or more simpler substances. AB A + B 2HgO 2Hg + O2 2KClO3 2KCl + 3 O2 a compound made of two elements, decomposes into those elements.

Decomposition YouTube - ammonium dichromate volcano

Decomposition Practice Predict the products. Then, write and balance the following decomposition reaction equations: Solid Lead (IV) oxide decomposes PbO2(s)  Aluminum nitride decomposes AlN(s) 

Decomposition Practice Predict the products. Then, write and balance the following decomposition reaction equations: Solid Lead (IV) oxide decomposes PbO2 (s)  Pb (s) + O2 (g) Aluminum nitride decomposes 2AlN(s) 2 Al (s) + N2 (g)

Learning Check 1 Classify the following reactions as 1) combination or 2) decomposition: ___A. H2 + Br2 2HBr ___B. Al2(CO3)3 Al2O3 + 3CO2 ___C. 4 Al + 3C Al4C3

Solution 1 Classify the following reactions as 1) combination or 2) decomposition: _1_A. H2 + Br2 2HBr _2_B. Al2(CO3)3 Al2O3 + 3CO2 _1_C. 4 Al + 3C Al4C3

Single Replacement (Displacement) One element takes the place of an element in a reacting compound. A + BC AC + B Zn + 2HCl ZnCl2 + H2 Fe + CuSO4 FeSO4 + Cu A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-). Whether one metal will displace another metal from a compound depends on the relative reactivity's of the two metals.

Single Replacement (Displacement) Practice YouTube - Thermite reaction

Single Replacement Displacement) Lithium Potassium Calcium Sodium Magnesium Aluminum Zinc Iron Lead Hydrogen Copper Mercury silver The activity series of metals lists metals in order of decreasing reactivity. A metal will replace any metal listed below.

Single Replacement (Displacement) Practice Sodium chloride solid reacts with fluorine gas NaCl(s) + F2(g)  Aluminum metal reacts with aqueous copper (II) nitrate Al(s)+ Cu(NO3)2(aq)

Single Replacement (Displacement) Practice Sodium chloride solid reacts with fluorine gas 2NaCl(s) + F2(g)  2 NaF(s) + Cl2(g) Note that fluorine (nonmetal) replaces chlorine (nonmetal) in the compound Aluminum metal reacts with aqueous copper (II) nitrate 2 Al(s)+ 3Cu(NO3)2(aq) 3Cu(s) + 2 Al(NO3)3

Double Replacement (Displacement) Two elements in reactants take the place of each other AB + CD AD + CB AgNO3 + NaCl AgCl + NaNO3 ZnS + 2HCl ZnCl2 + H2S

Double Replacement (Displacement) YouTube - Double Replacement Reactions

Double Replacement Practice Think about it like “foil”ing in algebra, first and last ions go together ; inside ions go together Example: AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq) Another example: K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s)

Double Replacement Practice Classify the following reactions as 1) single replacement 2) double replacement __A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 __B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 __C. 3C + Fe2O3 2Fe + 3CO

Double Replacement Practice Classify the following reactions as 1) single replacement 2) double replacement 1_A. 2Al + 3H2SO4 Al2(SO4)3 + 3H2 2_B. Na2SO4 + 2AgNO3 Ag2SO4 + 2NaNO3 1_C. 3C + Fe2O3 2Fe + 3CO

Double Replacement Practice Predict the products. Balance the equation HCl(aq) + AgNO3(aq)  2. CaCl2(aq) + Na3PO4(aq) 

Double Replacement Practice Predict the products. Balance the equation HCl(aq) + AgNO3(aq)  HNO3 + AgCl 2. CaCl2(aq) + Na3PO4(aq) Ca3(PO4)2 + NaCl

Combustion A reaction in which a hydrocarbon (compound made up of H and C) reacts with oxygen and the products are carbon dioxide and water CH4 + 2O2 CO2 + 2H2O C3H8 + 5O2 3CO2 + 4H2O

Combustion Combustion reactions occur when a hydrocarbon reacts with oxygen gas. This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”: 1) A Fuel (hydrocarbon) 2) Oxygen to burn it with 3) Something to ignite the reaction (spark)

Combustion Products in combustion are ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide)

Combustion Practice Complete and Balance the combustion equation ___C5H12 + ___O2

Combustion Practice Balance the combustion equation __C5H12 + _8_O2 5CO2 + _6H2O

Unit 8 Chemical Reactions Types of Reactions