unit 9 must knows duel

is H < 0 and S > 0 spontaneous at all Temps, delta G <0

anode

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

is H > 0 and S > 0 T = 500k spontaneous, high temperature, T delta S is large

voltage equation V = IR voltage = current (amps) * resistance (ohms)

charging a battery vs using a battery charging = non-spontaneous using = spontaneous

what is Gibb's free energy 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.

galvanic cell vs electrolytic cell galvanic = anode is negative and cathode is positive electrolytic = anode is positive and cathode is negative

volumes proportionality with entropy

entropy degrees of freedom of a molecule

1 joule of work / coulomb of charge transferred J/C = units

how K and G relate to each other G = negative = k>1 G = positive = k<1 k is close to 1, G is close to zero k is far from 1, G is far from zero

overall cell reaction y + z --> Y+ + Z- (G<0)

G, S, H S = entropy G = Gibbs free energy H = heat energy

delta G = delta H - (T * delta S) gibbs free energy = enthalpy - (temperature times entropy) *note T is in kelvin, not Celsius

a reaction can be coupled with a reaction that is favorable to push it forward Examples: - photosynthesis - ATP - Charging a battery with electricity

exergonic reaction products have less energy than reactants, spontaneous, graph will end lower than it started

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

oxidation half-reaction x --> X+ + e-

2nd law of thermodynamics entropy of an isolated system is never decreasing, only if it is in a 2 or more system

3rd law of thermodynamics as temperature goes to zero, entropy approaches a constant value

delta S = (sum of S products) - (sum of S reactants) DO NOT FORGET TO ACCOUNT FOR THE MOLES IN THE REACTION!!!

non-spontaneous is...

2nd law with entropy as matter disperses, entropy increase, so, going from solid to liquid to gas would increase entropy, whilst going from gas to liquid to solid would decrease it

if a reaction is kinetically favorable

is H < 0 and S < 0 T=100k spontaneous, low temperature, T delta S is small

Cell potential equation

1st law of thermodynamics

reduction happens, gaining electrons

Ecell = E (cathode) - E (anode) IMPORTANT: if the reaction gets reversed (in order to balance, sometimes it will need to be reversed), the sign of the Ecell must switch, however if it gets multiplied (in order to balance) IT REMAINS THE SAME!!

as temperature goes to zero, entropy approaches a constant value

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 as matter disperses, entropy increase, so, going from solid to liquid to gas would increase entropy, whilst going from gas to liquid to solid would decrease it

oxidation half-reaction

entropy of an isolated system is never decreasing, only if it is in a 2 or more system

volumes proportionality with entropy as V goes up, so does S as the more temperature, the more energy, the mor entropy

cell potential, Ecell, electromotive force (emf) 1 joule of work / coulomb of charge transferred J/C = units

how K and G relate to each other G = negative = k>1 G = positive = k<1 k is close to 1, G is close to zero k is far from 1, G is far from zero

delta G = delta H - (T * delta S) gibbs free energy = enthalpy - (temperature times entropy) *note T is in kelvin, not Celsius

what is Gibb's free energy 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.

products have less energy than reactants, spontaneous, graph will end lower than it started

charging a battery vs using a battery charging = non-spontaneous using = spontaneous

anode oxidation happens, losing electrons

cathode reduction happens, gaining electrons

delta G and the energy of the product is lower than that of the reactants 1. G = negative = k>1; G = positive = k

if a reaction is kinetically favorable it has k>1, relatively low activation energy

galvanic = anode is negative and cathode is positive electrolytic = anode is positive and cathode is negative

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

T = 500k spontaneous, high temperature, T delta S is large

is H < 0 and S > 0 spontaneous at all Temps, delta G <0

is H < 0 and S < 0 T=100k spontaneous, low temperature, T delta S is small

delta S = (sum of S products) - (sum of S reactants) DO NOT FORGET TO ACCOUNT FOR THE MOLES IN THE REACTION!!!

G, S, H S = entropy G = Gibbs free energy H = heat energy

how a reaction that is thermodynamically unfavorable occur a reaction can be coupled with a reaction that is favorable to push it forward Examples: - photosynthesis - ATP - Charging a battery with electricity

voltage equation V = IR voltage = current (amps) * resistance (ohms)

thermodynamically unfavorable

overall cell reaction y + z --> Y+ + Z- (G<0)

degrees of freedom of a molecule

End this game?