Question

Calculate the electronegativity of carbon from the following data:
Bond energy of H-H bond $E_{H-H}=104.2kcalmo{l}^{-1}$
Bond energy of C-C bond $E_{C-C}=83.1kcalmo{l}^{-1}$
Bond energy of C-H bond $E_{C-H}=98.8kcalmo{l}^{-l}$
Electronegativity of Hydrogen $X_H=\mathrm{2.1.}$

• A. 2.59
• B. -2.59
• C. -3.75
• D. 3.75

Answer 1

The correct option is A 2.59

Let the electronegativity of carbon be $X_C$. Applying Pauling equation, we get:
$X_C-X_H=0.208[E_{C-H}-(E_{C-C}\times E_{H-H}{)}^{0.5}{]}^{0.5}$
In this equation, bond energies are taken in $kcalmo{l}^{-1}$
$X_C-2.1=0.208[98.8-(83.1\times 104.2{)}^{0.5}{]}^{0.5}$
$X_C$ = 2.59