Question

The X -X bond length is 1 $\stackrel{\circ }{A}$ and Y - Y bond length is $1.54\stackrel{\circ }{A}$. If electronegativities of 'X' and 'Y' are 3.0 and 2.0 respectively, the X - Y bond length is likely to be

• A. $1.08\stackrel{\circ }{A}$
• B. $1.18\stackrel{\circ }{A}$
• C. $1.28\stackrel{\circ }{A}$
• D. $0.08\stackrel{\circ }{A}$

Answer 1

The correct option is B $1.18\stackrel{\circ }{A}$

Atomic radius of
$X=\frac{\text{Bond length}}{2}=\frac{1}{2}=0.5\stackrel{\circ }{A}$
Atomic radius of $Y=\frac{1.54}{2}=0.77\stackrel{\circ }{A}$
Hence,
using Stevenson equation, X - Y bond length = 0.5 + 0.77 - 0.09 $\times$ (3-2) $=1.18\stackrel{\circ }{A}$