Question

If C-C bond energy is 348 kJ/mol,C-H bond energy is 412kJ/mol and H-H bond energy is 436kJ/mol,the Pauling electronegativity of C ia about?(Given electronegativity of H=2.1)

Answer 1

Difference in the electronegativity of carbon and hydrogen can be calculated using the equation as follows:

$X_{C}}-X_{H}= (eV)^{-1/2}(E(HC)-\frac{E(CC)+E(HH}{2})^{-1/2}$

Here,

$X_{C}$

=electronegativity of carbon

$X_{H}$

=electronegativity of hydrogen=2.1

E(HC)=energy of HC bond= 412 KJ mol⁻¹  

E(CC)=energy of CC bond= 348 KJ mol⁻¹  

E(HH)=energy of HH bond= 436 KJ mol⁻¹  

Putting the values in the equation;

$X_{C}-X_{H}= (eV)^{\frac{-1}{2}}(412-\frac{348+436}{2})^{\frac{-1}{2}}$

                            =0.22      

$X_{C}= 0.22+2.1$

$X_{C}= 0.22+2.1$

                  = 2.32

So, the electronegativity of C is 2.32