Term
how much do transport processes contribute to electrochemical kinetics measurements? 

Definition


Term
transport processes are based on __ 

Definition


Term
hydrodynamics is described with what type of mathematics? 

Definition


Term
in eqn 7.1, J_{i} = D_{i}*grad(c_{i})  [z_{i}*F/(R*T)]D_{i}*c_{i}*grad(phi) + c_{i}*v
the first term represents __ 

Definition


Term
in eqn 7.1, J_{i} = D_{i}*grad(c_{i})  [z_{i}*F/(R*T)]D_{i}*c_{i}*grad(phi) + c_{i}*v
the second term represents __ 

Definition


Term
in eqn 7.1, J_{i} = D_{i}*grad(c_{i})  [z_{i}*F/(R*T)]D_{i}*c_{i}*grad(phi) + c_{i}*v
the third term represents __ 

Definition


Term
define potentiostatic regime 

Definition
currenttime dependence at constant potential 


Term
current measurements in the potentiostatic regime can be used to find what 3 things? 

Definition
diffusion layer thickness time dependence of diffusion layer thickness
diffusion coeff. of electrochemically active species 


Term
define galvanostatic regime 

Definition
currenttime dependence at constant current 


Term
two key equations for transport processes in electrochem. systems are the __ and __ 

Definition
flux vector eqn
molar conc. vs time eqn 


Term
in order to set up a constant potential so that current density vs. time can be measured, what is needed? 

Definition
a 3electrode system and a potentiostat 


Term
under a galvanostatic regime and when the chargetransfer reaction is fast, the conc. gradient at the electrode surface is __ 

Definition


Term

Definition
time to achieve 0 concentration at the electrode surface 


Term
list 2 ways that galvanostatic measurements can be used 

Definition
1. to define the diffusion coeff. if bulk concentration is known
2. as an analytical tool to measure concentration of the electrochemically active species if the diffusion coeff. is known 


Term
galvanostatic measurements can be used to define the diffusion coeff. if... 

Definition
bulk concentration is known 


Term
galvanostatic measurements can be used as an analytical tool to measure concentration of the electrochemically active species if... 

Definition
the diffusion coeff. is known 


Term
name 2 ways electrochemical processes can be influenced 

Definition
by mass transport due to diffusion
by convection 


Term
in eqn 7.7, (∂c_{i}/∂t) = D_{i}*Lap^2*c_{i}  v*grad(c_{i})
the first term represents __ 

Definition


Term
in eqn 7.7, (∂c_{i}/∂t) = D_{i}*Lap^2*c_{i}  v*grad(c_{i})
the second term represents __ 

Definition


Term
for eqn 7.7, (∂c_{i}/∂t) = D_{i}*Lap^2*c_{i}  v*grad(c_{i})
it is assumed that when convection in the electrochemical cell is changed, the Nernst diffusion layer is changed or unchanged? 

Definition


Term
cell current depends on hydrodynamics because... 

Definition
when convection in the electrochemical cell is changed, the Nernst diffusion layer is also changed 


Term
as the intensity of mixing increases, the length of the diffusion layer 

Definition
decreases (more intensive mixing = smaller diffusion layer) 


Term
Prandtl layer thickness pertains to velocity of solution or to concentration of the electrochemically active species? 

Definition


Term
Nernst diffusion layer thickness pertains to velocity of solution or to concentration of the electrochemically active species? 

Definition
concentration of the electrochemically active species 


Term
at the distance below the Prandtl layer thickness, what happens to velocity of the solution? 

Definition
velocity begins to drop, reaching zero at the electrode surface 


Term
at the distance below the Nernst diffusion layer thickness, what happens to concentration of the electrochemically active species? 

Definition
concentration begins to drop, reaching zero at the electrode surface 


Term
which typically represents a greater distance from the electrode surface, Prandtl layer thickness or Nernst diffusion layer thickness? 

Definition


Term
which typically drops faster when approaching the electrode surface, velocity of the solution or the concentration of the electrochemically active species? 

Definition
concentration of the electrochemically active species 


Term
when solution current is parallel to the electrode surface and perpendicular to the diffusion direction... 

Definition
1. Nernst diffusion layer thickness is changing with the length of the electrode
2. the electrode is not equally accessible in the direction of the solution flow 


Term
for most systems, if there is mixing of the solution, the Nerst diffusion layer thickness is __ 

Definition


Term
one of the systems where the Nerst diffusion layer thickness is precisely defined is __ 

Definition


Term

Definition


Term
what is the main feature of the RDE? 

Definition
it is equally accessible at all points on the electrode surface 


Term
for the RDE, Nernst diffusion layer thickness depends on what 3 things? 

Definition
1. diffusion coeff. of the electrochemically active species
2. viscosity and density of the solution 3. rotation rate of the RDE 


Term
for the RDE, the limiting current density can be calculated if... 

Definition
the bulk concentration of the electrochemically active species is known 


Term
for the RDE, as angular velocity (and hence the rotation rate) of the electrode increases, limiting current density __ 

Definition
increases
(high ang. velocity = high j_{lim}) 


Term
for the RDE, if you plot limiting current vs. the square root of angular velocity, the shape of the line is __ 

Definition
a straight line that goes through the origin 


Term
for the RDE, calculating the limiting current density at infinite angular velocity is possible or impossible? 

Definition


Term
for the RDE, when angular velocity is infinite, the Nernst diffusion layer thickness equals __ 

Definition


Term
at high overpotentials, the limiting current... 

Definition
is entirely determined by transport processes and is therefore independent of potential 


Term
what kind of cell should be used with the RDE? 

Definition


Term
to get high quality data, the RDE should be __ 

Definition


Term
to study the electrochemical kinetics of a redox reaction, out of what material should the RDE ideally be made? 

Definition
platinum
(other materials *can* be used if clean and polished, but Pt is best) 


Term
for the RDE, the current density at infinite angular velocity can be used with what equation to calculate exchange current density and symmetry coefficients for the RDE electrochemical reaction? 

Definition

