unit 9 must knows duel

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

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

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

cell potential, Ecell, electromotive force (emf)

G, S, H

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

anode oxidation happens, losing electrons

is H > 0 and S > 0

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.

is H < 0 and S > 0

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

1st law of thermodynamics

is H < 0 and S < 0

oxidation half-reaction

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

charging = non-spontaneous using = spontaneous

2nd law of thermodynamics

how K and G relate to each other

entropy

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

cathode reduction happens, gaining electrons

2nd law with entropy

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

overall cell reaction

Cell potential equation 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!!

non-spontaneous is...

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

3rd law of thermodynamics

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

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

in an isolated system energy can neither be created or destroyed; only transferred or converted, meaning E lost = negative E gained

entropy

reduction happens, gaining electrons

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.

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

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

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

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

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

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

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!!

3rd law of thermodynamics

anode

thermodynamically unfavorable

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

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

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

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

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

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

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

is H > 0 and S > 0

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

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

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

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

End this game?