Chemistry 11 unit 2 - Chemical Reaction

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Chemistry 11 unit 2 - Chemical Reaction

Oxidation and reduction, Reactions or Redox reaction

2HCl(ap)+2Na(s) - 2NaCl(aq)+H2

2Cl- --2Cl- = spectatorion (did nothing)

2H+ + 2e - H2 (o) = reduced

2Na - 2Na (+1) + 2e +oxidized

Na more reactive than hydrogen, so it replace H

Reduction - Gain of electrons from an atom/ion.. / more hydrogen bond

O2 +4e - 2O-2 (reduced

Oxidation - Loss of e- from an atom / more bonds to oxygen

2Mg - 2Mg^+2 = -4e- (oxidized)

5 Main Types of Chemical Reactions

Combustion: Oxide creation (O2)

Double Displacement: AB+ CD -AC+BD

Single Displacement: AB+CD - AC+BD

Decomposition: AB - A+B

Synthesis: A+B -AB

Balancing Equations

Always balance C, O2, H2, Cl2, Al last

H2So4+2NaOH - NaSo4+2H2O

If a polyatomic exist in the same form on both side, count them as one element

How the same amount of each element on reactant and product side

Reflects the law of conservation of matter

Double Displacement RXN (RXN) = Reaction

A double displacement will occur if the dissociated hydrated ions come out of solution

This can happen in 3 ways

A covalent gas is formed

2) A covalent liquid (mostly H2O) is formed

1) An insoluble solid (precipitate) for mass - refer to solubility table

Small ions with big charge tend to be insoluble because the attraction between is very strong

Note precipitates, do not dissociate so are written associated in total ionic equation

2 aqueous (aq) ionic solution = NR

CaCl2(aq) +KBr (aq) -KCL(aq) + CaBr2 (aq)

Positive go with negative

Then check the solubility table

This case nothing changed, so it's an NR (No Reaction)

Always to write the right equation by using the crossover rule