electrochemistry

Reduction

• Gain of electrons (e on reactants side)

• Substance that is reduced is the oxidizing agent (high Ep°)

• Cathode

Oxidation

• Loss of electrons (e on products side)

• Substance that is oxidized is the reducing agent (low Ep°)

• Anode

How to balance

1. find the atom that are reduced and oxidized

2. write skeleton equation for each

3. balance with major OH-

4. multiply to equalize electrons

5. combine to make net equation

Energy cell potential formula

Ecathode - Eanode

Energy minimum formula

Eanode - Ecathode

Cell stoic, charge formula

Q = Lt

cell stoic combined formula

ne = lt/F

(F = 9.65 × 10 ^ 4)

cell stoic mole formula

n = ne/number of electrons per 1 molecule

mass loss/gain

solid to aqueous = loses mass
aquaous to solid = gain mass

voltaic cell

• cathode will be the one with higher reduction potential

electroytic cell

• if cation is higher than R. of water (-0.83) it is cathode

• if anion is lower than Ox. of water (1.23) it is anode

determine if something can reduce other

lower Ep° reduces higher Ep°

determine if something can oxidize other

higher Ep° oxidizes the lower Ep°

titration

1. write net equation from the half reactions from table

2. the higher substance is the reaction that is reduction (written forwards)
   3. combine both reduction and oxidation half reactions
   4. find the coeficets and plug into formula

titration formula

(n is the coeficent on the substance from the balanced equation)

corrosion

use water half reaction at +0.40