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Question 1

Why don’t large anions have a water sheath?

Answer 1

water sheath around cations are more stable because of steric effects

Question 2

What steps occur in a cathode reaction?

Answer 2

> diffusion of hydrated cation to electrode
dehydration of cation
adsorption of cation onto electrode surface
transfer of e- from electrode to cation
incorporation of resulting atom into solid matrix

Question 3

Normality

Answer 3

moles of charge per liter of soln

Question 4

Molarity

Answer 4

moles per liter of soln

Question 5

Molality

Answer 5

moles per kg of solvent

Question 6

Faradaic processes

Answer 6

amount of chemical change is equal to amount of current passed

Question 7

Faraday’s 1st law

Answer 7

> when current passes through a solution, the amount of material coming in or going out is prop to amount of energy coming through
charge Q = I*t

Question 8

Faraday’s 2nd law

Answer 8

> weights of substances deposited or dissolved by the passage of certain quantity of electricity are proportional to their equivalent weights
m = a/n = molar mass / valence # of ions

Question 9

m =

Answer 9

Ita/nF

Question 10

Q =

Answer 10

nFη
> n: charge # of electrode in rxn
> η: # of moles

Question 11

Current is proportional to

Answer 11

corrosion rate

Question 12

Non-Faradaic processes:

Answer 12

> change w/out charge transfer
change in structure of electrode/soln interface by changes in potential or solution composition
no e- flow through electrode/electrolyte interface
transient external currents can be generated

Question 13

Equivalent weight We =

Answer 13

a/ηeF

Question 14

Corrosion rate:

Answer 14

> (mils/year or mpy): 534W/dat
(mm/yr): 87.6W/dat

W: weight change (kg)

d: density
a: area (in^2)
t: time (hrs)

Question 15

What makes water a good solvent?

Answer 15

> non-linear molecule
electric dipole
H2O particles bond tetragonally and electrostatically by short range order
salts dissolve chemically, no change in oxidation state