Question

$PC{l}_5$ has a shape of trigonal bipyramidal whereas $I{F}_5$ has a shape of square pyramidal, it is due to-

• A. Presence of unshared electron pairs on $I$ which is oriented so as to minimise repulsion while in $PC{l}_5$ has no non-bonding pair.
• B. Octet of $P$ is complete whereas that of $I$ is incomplete.
• C. $P$ and $I$ belong to different group and period.
• D. Extent of different repulsion in $F$ and $I$

Answer 1

The correct option is A Presence of unshared electron pairs on $I$ which is oriented so as to minimise repulsion while in $PC{l}_5$ has no non-bonding pair.

$PC{l}_5$ $\to$ $s{p}^{3}d$ hybridised orbitals with no non-bonding pair (trigonal bipyramidal)

$I{F}_5$ $\to$ $s{p}^3{d}^2$ hybridised orbitals with one non bonding pair (square pyramidal)