Pauling's electronegativity

Pauling's electronegativity

1. Pauling electronegativity
Dr. Mithil Fal Desai
Shree Mallikarjun and Shri Chetan Manju Desai College
Canacona Goa

2. LinusPaulingdescribedelectronegativity
as“thepowerofanatominamoleculeto
attractelectronstoitselfwhencombined
inacompound.”
Linus Pauling
Definition of Electronegativity
e
-
e
-
Atom A
Atom B
e
-
e
-

3. Calculating Electronegativity
A B
Thefactor0.208arisesfromtheconversion
electronegativityvaluesfromKcalstoelectronvolt.

4. Calculating Electronegativity
A B
E
A-B> E
A-A or E
B-B
E
A-B(measured)> E
A-B(theoretical)
Difference in the Bond Energies (Δ)
Δ = E
A-B(measured)–E
A-B(theoretical)
E
A-B(theoretical) = energy for 100% covalent bond
E
A-B(theoretical) = (E
A-A X E
B-B)
1/2
Thus
Δ= E
A-B(measured)–(E
A-A X E
B-B)
½
δ+ δ-
IfX
(A)andX
(B)are
electronegativityofindividual
atomsAandB,respectively,
than
X
(A)-X
(B)= 0.1017(Δ)
½
in kJ mol
-1
X
(A)-X
(B)= 0.208 (Δ)
½
in kcal mol
-1

5. Periodic trend in Electronegativity
Pauling’s electronegativity values are
measured in electron volt (eV).

6. Summary
•Fismostelectronegativeelement
•Iftwoelementhavesimilar(<1.7)electronegativity
valuesthebondiscovalentormetallic.
•Iftwoelementhavelarge(>1.7)differenceintheir
electronegativityvaluesthebondisionic
predominantly.
As Atomic number increases
•Electronegativity decreases down the group
•Electronegativity increases along the row

7. References
•Lee,J.D.,(2018),ConciseInorganicChemistry,FifthEdition,New
Delhi,WileyIndia.
•Huheey,J.E.,Keiter,E.A.,Keiter,R.L.,Medhi,O.K.,(2019)Inorganic
Chemistry:Principleofstructureandreactivity,FourthEdition,Noida,
PearsonEducationIndia.
•Atkins,P.,OvertonT.,Rourke,J.,Weller,M.,ArmstrongF.,(2006)
ShriverandAtkin’sInorganicChemistry,FourthEdition,GreatBritain,
OxfordUniversityPress.