Question

the molecular geometric shape of icl₃ molecule is best described as
a trigonal bipyramidal
b trigonal planar
c seesaw
d t - shaped

Explanation:

Step1: Calculate the number of valence electrons and electron - pair geometry

• Iodine (\(I\)) has \(7\) valence electrons and each chlorine (\(Cl\)) has \(7\) valence electrons. So for \(ICl_{3}\), the total number of valence electrons is \(7+(3\times7)=28\).
• The central atom \(I\) forms \(3\) single bonds with \(Cl\) atoms. The number of bonding pairs (\(BP\)) is \(3\). The number of lone pairs (\(LP\)) on \(I\) is \(\frac{7 - 3}{2}=2\) (using the formula \(LP=\frac{V - BP}{2}\), where \(V\) is the valence electrons of the central atom).
• The electron - pair geometry is trigonal bipyramidal (because the sum of \(BP + LP=3 + 2=5\)).

Step2: Determine the molecular geometry

• In a trigonal bipyramidal electron - pair geometry, when there are \(2\) lone pairs, they occupy the equatorial positions (to minimize repulsions).
• The molecular geometry of \(ICl_{3}\) is T - shaped.

Answer:

D. T - shaped