cathode
reduction happens, gaining electrons
volumes proportionality with entropy
G, S, H
S = entropy
G = Gibbs free energy
H = heat energy
exergonic reaction
entropy
degrees of freedom of a molecule
spontaneous at all Temps, delta G <0
oxidation half-reaction
1st law of thermodynamics
in an isolated system energy can neither be created or destroyed; only transferred or converted, meaning E lost = negative E gained
galvanic = anode is negative and cathode is positive
electrolytic = anode is positive and cathode is negative
is H > 0 and S > 0
T = 500k
spontaneous, high temperature, T delta S is large
if a reaction is thermodynamically favorable
delta G and the energy of the product is lower than that of the reactants
1. G = negative = k>1; G = positive = k
(sum of S products) - (sum of S reactants)
DO NOT FORGET TO ACCOUNT FOR THE MOLES IN THE REACTION!!!
how K and G relate to each other
charging = non-spontaneous
using = spontaneous
delta G = delta H - (T * delta S)
gibbs free energy = enthalpy - (temperature times entropy)
*note T is in kelvin, not Celsius
if a reaction is kinetically favorable
1 joule of work / coulomb of charge transferred
J/C = units
V = IR
voltage = current (amps) * resistance (ohms)
Cell potential equation
is H < 0 and S < 0
T=100k
spontaneous, low temperature, T delta S is small
galvanic cell
chemical energy is converted to electrical energy with spontaneous redox reaction
Voltage
consists of oxidizing agent in one compartment that pulls electrons through a wire from a reducing agent
2nd law with entropy
2nd law of thermodynamics
non-spontaneous is...
the energy of a system related to changes in enthalpy and entropy, at a constant temperature.
basically implies that the system is at 1 atm and using 1 M solutions.
anode
oxidation happens, losing electrons
3rd law of thermodynamics
as temperature goes to zero, entropy approaches a constant value
overall cell reaction
y + z --> Y+ + Z- (G<0)
how a reaction that is thermodynamically unfavorable occur
