Question

Consider the following reaction:
$H_2\left(g\right)+F_2\left(g\right)\to 2HF\left(g\right)$
Is the $H-F$ bond more or less polar than $H-H$ bond?

• A. The $H-F$ bond is less polar than an $H-H$ bond
• B. The $H-F$ bond is more polar than an $H-H$ bond
• C. Both the bond are having same polarity
  
• D. None of the above
  

Answer 1

The correct option is B The $H-F$ bond is more polar than an $H-H$ bond

Greater is the electronegativity difference between the bonded atoms, greater will be the polarity of the bonds.In $H-H$ bond, both atoms are same, the electronegativity difference is zero. Hence $H-H$ bond is non-polar. Whereas the $H-F$ bond is polar due to a significant difference in the electronegativity between $H$ and $F$. $H$ is electropositive and $F$ is electronegative.