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Types of Reactions. 11.2 & 11.3 Notes. Combustion. oxygen combines with a reactant “burning” Common products: H 2 O and CO 2 (but not always!) X + O 2 --> Y examples: N 2 (g) + O 2 (g) --> 2NO (g) CH 4 (g) + 2 O 2 (g) --> 2 H 2 O (g) + CO 2 (g). Synthesis.
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Types of Reactions 11.2 & 11.3 Notes
Combustion • oxygen combines with a reactant • “burning” • Common products: H2O and CO2(but not always!) • X + O2 --> Y • examples: • N2 (g) + O2 (g) --> 2NO (g) • CH4(g) + 2 O2(g) --> 2 H2O (g) + CO2 (g)
Synthesis • two or more reactants are combined into a single product • A + B --> AB • example: 2 Pb (s) + O2 (g) --> 2 PbO (s)
Decomposition • a reactant breaks down into two or more products • AB --> A + B • example: • Ni(OH)2 (s) --> NiO (s) + H2O (l)
Single - Replacement • atoms of one element replace the atoms of another element in a compound • The element that displaces the other must be more ‘active’ based on activity series. • A + BY --> B + AY • example: • Cl2(g) + MgBr2(aq) --> Br2(l) + MgCl2(aq)
Double - Replacement • ions in two compounds are exchanged/ swapped • AB + XY --> AY + XB • example: • 2 NaOH (aq) + CuCl2(aq) --> 2NaCl (aq) + Cu(OH)2(s)
sToP & tHinK • Categorize according to the reaction type. a) 2 Cu + O2 --> 2 CuO b) Fe + 2 NaCl --> FeCl2 + 2 Na c) 2 KOH + CuBr2 --> 2 KBr + Cu(OH)2 d) 2 MgO --> O2 + 2 Mg e) 2 Na + Cl2 --> 2 NaCl
Activity Series • Shows how reactive an element is… • higher activity elements will replace lower activity elements in single replacement reactions
sToP & tHinK • Which is more active in each of these two pairs? • Chlorine or Bromine? • Magnesium or Copper? • Would the following reaction occur? Explain. • FeCl2 + 2 Na --> Fe + 2 NaCl
Reactions in Aqueous Solutions • Ionic compounds “dissociate” in solution - the ions break apart (click for animation) • complete ionic equation - write all ions separately (not as compounds) • net ionic equation - includes only ions that react • spectator ions - the ions that are the same on both sides of arrow
Example • reaction equation: (write formulas) • CuCl2 (aq) + 2 NaOH (aq) --> 2 NaCl (aq) + Cu(OH)2 (s) • complete ionic equation: (separate ions) • Cu2+ (aq) + 2 Cl- (aq) + 2Na+ (aq) + 2OH- (aq) -->2 Cl- (aq) + 2Na+ (aq) + Cu(OH)2 (s) • net ionic equation: (only write substances that don’t cancel) • Cu2+ (aq) + 2OH- (aq)--> Cu(OH)2 (s) • what were the spectator ions?
sToP & tHinK • Write the complete ionic and net ionic equation for this reaction. Identify the spectator ions. • BaCl2 (aq) + Na2SO4 (aq) -->