Oxidation is the process when oxidation number of element increases, lose electrons, adds oxygen, loses hydrogen, electrons as product in half-reaction
Reduction is oxidation number of element decreases, element gains electrons, loses oxygen, gains hydrogen, half-reaction has electrons as reactants
oxidizing agent: substance that is reduced
reducing agent: substance that is oxidized
anode: electrode where oxidation occurs
cathode: electrode where reduction occurs
current: number of electrons that flow through system per second(coulomb/second)(ampere)
1 coulomb = 6.25 * 10^18 electrons
surface area increases current
voltage=difference in potential energy between the reactants and products, potential difference in volts
1 V = 1 J of energy per coulomb of charge, needed to drive electrons through external circuit
amount of force pushing the electrons through the wire is called electromotive force, emf
Difference in potential energy between the anode and cathode in a voltaic cell is the cell potential
cell potential depends on relative ease with which the oxidizing agent is reduced at the cathode and the agent is oxidized at the anode
cell potential under standard conditions is called E naught cell (1 M)
cannot exactly measure tendency of a half-reaction, measure relative to reduction of H+ under the standard condition, potential difference 0V(standard hydrogen electrode, SHE)
half-reactions with a stronger tendency toward reduction have a positive value for E cell
half-reactions with a stronger tendency toward oxidation have a negative value for E cell
For an oxidation half-reaction, E oxidation = - E reduction
E cell - E oxidation + E reduction
When adding .E values, do not multiply the half cell E values
a redox reaction will be spontaneous when there is strong tendency for the oxidizing agent to be reduced and the reducing agent to be oxidized, positive to be spontaneous