Question

The bond lengths of A –A and B – B bonds are 1.6 and 2.0 Å, respectively. If the electronegativities of A and B are 2.8 and 2.1, respectively, the according to Schomaker and Stevenson's Equation, the bond length of A– B bond should be:

• A. 3.537 Å
• B. 2.973 Å
• C. 1.737 Å
• D. 1.567 Å

Answer 1

The correct option is C 1.737 Å

We know that,
$d_{AB}=r_A+r_B–0.09\left[\Delta EN\right]$
where $\Delta EN$ is electronegativity difference between A and B and $r_A$ and $r_B$ are respectively the atomic radii of A and B (half of bond lengths of A-A and B-B)
$d_{AB}=\frac{1.6}{2}+\frac{2.0}{2}-0.09(2.8-2.1)$
$d_{AB}=1.737\AA$