Driving Forces
geen entropieproductie, (dynamisch) evenwicht
exotherm, endotherm, atherm (tekening energieniveaus)
constant volume en temperatuur: go to = helmholtz energy (extremum principle)
drukverschil doordat de piston een massa heeft, kan ook komen door verschil
stoichiometrische coëfficiënten in de reactie
Chapter 1 Driving Forces
driving force causes flux
if driving force is zero; equilibrium (no driving force? also no flux)
difference in temperature is driving force for heat flow (=heat flux)
if heat flux becomes zero → thermal equilibrium
difference in pressure causes volumetric change
volumetric flux is speed of piston
if volumetric flux becomes zero → mechanical equilibrium
- only if piston has negligible mass & if there’s friction)
difference in amount of substance is molecular flux
molecular flux caused by concentration gradient; diffusion
difference in interactions also generates molecular flux
chemical potential: effects of concentration gradient & difference in interaction on molecular
flux
difference in electric potential causes movement of charged particles
driving forces are intensive quantities that causes an extensive quantity to change
intensive and extensive
getting more of system
- intensive quantities remain the same (temperature, pressure, concentration, density, electrical potential)
- extensive quantities scale with size of system (amount, mass, energy, entropy, volume)
dividing two extensive quantities → intensive quantity (molar quantities (volume/amount = molar volume)
state quantity is property of system (temperature eg)
no state quantity: heat, work, time
if no friction → no energy lost to surroundings
dispersal of energy gives direction to process
driving forces arise only when energy is dispersed
marble in bowl: friction leads to hinder in movement of marble; it experiences friction force
friction force is driving force that drives system to state in which marble is eventually at rest
driving forces and corresponding fluxes are related to entropy production
Chapter 2 Driving force behind molecular flux
𝐹𝑓𝑟 = 𝑓𝑣 (frictional force = frictional coefficient * velocity)
𝑢 = 1/𝑓 (mobility = 1/frictional coefficient)
particles in solution move, under influence of external field, in direction depending on density
and charge of particles
Stokes’ equation: 𝑓 = 6πη𝑟 (frictional coefficient = 6pi * viscosity * radius)
geen entropieproductie, (dynamisch) evenwicht
exotherm, endotherm, atherm (tekening energieniveaus)
constant volume en temperatuur: go to = helmholtz energy (extremum principle)
drukverschil doordat de piston een massa heeft, kan ook komen door verschil
stoichiometrische coëfficiënten in de reactie
Chapter 1 Driving Forces
driving force causes flux
if driving force is zero; equilibrium (no driving force? also no flux)
difference in temperature is driving force for heat flow (=heat flux)
if heat flux becomes zero → thermal equilibrium
difference in pressure causes volumetric change
volumetric flux is speed of piston
if volumetric flux becomes zero → mechanical equilibrium
- only if piston has negligible mass & if there’s friction)
difference in amount of substance is molecular flux
molecular flux caused by concentration gradient; diffusion
difference in interactions also generates molecular flux
chemical potential: effects of concentration gradient & difference in interaction on molecular
flux
difference in electric potential causes movement of charged particles
driving forces are intensive quantities that causes an extensive quantity to change
intensive and extensive
getting more of system
- intensive quantities remain the same (temperature, pressure, concentration, density, electrical potential)
- extensive quantities scale with size of system (amount, mass, energy, entropy, volume)
dividing two extensive quantities → intensive quantity (molar quantities (volume/amount = molar volume)
state quantity is property of system (temperature eg)
no state quantity: heat, work, time
if no friction → no energy lost to surroundings
dispersal of energy gives direction to process
driving forces arise only when energy is dispersed
marble in bowl: friction leads to hinder in movement of marble; it experiences friction force
friction force is driving force that drives system to state in which marble is eventually at rest
driving forces and corresponding fluxes are related to entropy production
Chapter 2 Driving force behind molecular flux
𝐹𝑓𝑟 = 𝑓𝑣 (frictional force = frictional coefficient * velocity)
𝑢 = 1/𝑓 (mobility = 1/frictional coefficient)
particles in solution move, under influence of external field, in direction depending on density
and charge of particles
Stokes’ equation: 𝑓 = 6πη𝑟 (frictional coefficient = 6pi * viscosity * radius)
