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Formulae For
ELECTROCHEMISTRY
By Mir Mohammed Abbas II PCMB 'A'
FORMULAS- ELECTROCHEMISTY
Important Terms, Definitions & Formulae
XII Chemistry
CHAPTER 3 - ELECTROCHEMISTRY
1.
2.
3.
4.
Eө
cell
= Eө
cathode
– Eө anode
0.059
1
log n+ (At 298 K)
n
[M ]
2.303RT
[Anode ion]
Ecell = Eөcell log
nF
[Cathode ion]
0.059
log K c (At 298 K)
Eөcell =
n
E = Eө -
5.
∆Gө = -nFEөcell
6.
R=ρ
7.
Conductance:G =
8.
Conductivity = Conductance × Cell constant
9.
1 1 l
l
κ = = ( ) =G
A
ρ R A
l
1 l
=
A κ A
1
R
*
10. Cell constant and is denoted by the symbol G
Specific conductance
=
Molarity
κ x 1000
=
C
11.
Λm =
12.
Λm
κ
C
Remember:
Unit of Λm in above formula is Scm2mol-1
∧c
13. α = m
0
∧m
14. K a =
c α2
1-α
FORMULAS- ELECTROCHEMISTRY
15. Kohlrausch’s Law of independent migration of ions:
If the limiting molar conductivity of the cations is denoted by λo+ and that of
the anions by λo− then the limiting molar conductivity of electrolyte is:
0
∧m
= ν + λ0+ + v − λ0−
Where v+ and v- are the number of cations and anions per formula of
electrolyte.
16. Faraday constant: It is equal to 96487 C mol-1 or approximately equal to
96500 C mol-1.