Question

Which of the following is/are the correct characteristics of anionic part of 'X'?
[Polar and non-polar nature to be considered on the basis of dipole moment]
(I) Planar
(II) non-planar
(III) Polar
(IV) non-polar

• A. I and III
• B. I and IV
• C. II and III
• D. II and IV

Answer 1

The correct option is B I and IV

When $KI$ and $I_2$ reacts, it forms $I_3^{-}$

$KI+I_2\to K^{+}+I_3^{-}$

So, the species $X$ formed is $I_3^{-}$.

It undergoes $s{p}^{3}d$ hybridization with linear geometry.

The anionic part of X that is $I^{-}$ is planar and non-polar.
Because all the lone pair and the bonded atoms with the central atom lie on the same plane. The anionic part is non-polar because the electronegativity difference between the bonded adjacent atom is Zero. Consequently, dipole moment is zero.

Hence, $I$ & $IV$ are correct.