Question

The bond dissociation energy of H - H, C - C, and C - H bonds respectively are 104.2, 83.1 and 98.8 kcal/ mole. The electronegativity of C is?

• A. 2.53
• B. 2.51
• C. 2.50
• D. 2.52

Answer 1

The correct option is A

2.53

$△$ = $E_{C-H}$ - $\sqrt{E_{H-H}\times E_{C-C}}$

= 98.8 - ${\left[\right(104.2)\times (83.1\left)\right]}^{\frac{1}{2}}$ = 5.75 kcal.

($X_{C-H}$) E.N of C-H bond = 0.218 $\sqrt{△}$ = 0.218 ${\left(5.75\right)}^{\frac{1}{2}}$

= 0.43

$X_C$ = 0.43 + $X_H$ = 0.43 + 2.1 = 2.53