Ch. 8 Chemical Equations and Reactions 8.2a Types of Chemical Reactions

Types of Chemical Reactions 5 basic types discussed here not all reactions fall in these categories you should be able to: categorize a reaction by its reactant(s) predict the product(s)

1. Synthesis also called composition reaction reactants: more than one can be elements or compounds products: only one compound A + X  AX where A is the cation and X is anion

1. Synthesis Rubidium and sulfur Rb(s) + S8(s)  Rb2S(s) Magnesium and oxygen Mg(s) + O2(g)  MgO(s) Sodium and chlorine Na(s) + Cl2(g)  NaCl(s) Magnesium and fluorine Mg(s) + F2(g)  MgF2(s)

1. Synthesis calcium oxide and water CaO(s) + H2O(l)  Ca(OH)2(aq) sulfur dioxide and water SO2(g) + H2O(l)  H2SO3(aq) calcium oxide and sulfur dioxide CaO(s) + SO2(g)  CaSO3(s)

2. Decomposition opposite of synthesis usually require energy reactants: only one compound products: more than one usually elements but can be compounds AX  A + X

2. Decomposition water H2O(l)  H2(g) + O2(g) calcium carbonate CaCO3(s)  CaO(s) + CO2(g) calcium hydroxide Ca(OH)2(s)  CaO(s) + H2O(l) carbonic acid H2CO3(aq)  CO2(g) + H2O(l)

3. Single Replacement an element replaces a similar element in a compound reactants: 1 element & 1 compound products: 1 element & 1 compound A + BX  B + AX Y + AX  X + AY

3. Single Replacement zinc and hydrochloric acid Zn(s) + HCl(aq)  ZnCl2(aq) + H2(g) iron and water Fe(s) + H2O(l)  FeO(aq) magnesium and lead (II) nitrate Mg(s) + Pb(NO3)2(aq)  Mg(NO3)3(aq) + Pb(s) chlorine and potassium bromide Cl2(g) + KBr(s)  KCl(s) + Br2(g)

4. Double Replacement two similar elements switch places reactants: 2 compounds products: 2 compounds AX + BY  BX + AY

4. Double Replacement barium chloride and sodium sulfate BaCl2(aq) + Na2SO4(aq)  NaCl(aq) + BaSO4(s) iron sulfide and hydrochloric acid FeS(aq) + HCl(aq)  FeCl2(aq) + H2S(g) hydrochloric acid and sodium hydroxide HCl(aq) + NaOH  NaCl(aq) + H2O(l) potassium iodide and lead (II) nitrate KI(aq) + Pb(NO3)2  KNO3(aq) + PbI2(s)

5. Combustion combines with oxygen releases energy in form of heat/light reactants: O2 + compound/element compound or element must be made of C and H only H2O and/or CO2 depending on element contained in reactants Ex: CH4 + O2  CO2 + H2O

C3H8(g) + O2(g)  CO2(g) + H2O(g) Combustion hydrogen and oxygen H2(g) + O2(g)  H2O(g) propane and oxygen C3H8(g) + O2(g)  CO2(g) + H2O(g)

Practice Classify each of the following reactions one of the five basic types: Na2O + H2O  NaOH synthesis Zn (s) + 2HCl(aq)  ZnCl2(aq) + H2(g) single replacement Ca(s) + 2H2O(l)  Ca(OH)2(aq) + H2(g)

Practice C2H4(g) + O2(g)  CO2(g) + H2O(g) 2H2O2(aq)  O2(g) + 2H2O(l) decomposition Cu(s) + 2AgNO3(aq)  2Ag(s) +Cu(NO3)2(aq) single replacement C2H4(g) + O2(g)  CO2(g) + H2O(g) combustion ZnO(s) + C(s)  2Zn(s) + CO2(g)

Practice Na2O(s) + 2CO2(g) + H2O(l)  NaHCO3(s) synthesis Ca(s) + H2O(l)  Ca(OH)2 (aq) + H2(g) single replacement KClO3(s)  KCl(s) + O2(g) decomposition H2SO4(aq) + BaCl2(aq)  HCl(aq) + BaSO4(s) double replacement