Question

Identify the correct statement about \(ClF_3\).

• A. It has T-shaped geometry with three lone pairs on Cl atom.
• B. It has planar trigonal geometry with two lone pairs on Cl atom.
• C. It has T-shaped geometry with two lone pairs on Cl atom.
• D. It has trigonal pyramidal geometry with two lone pairs on Cl atom.

Hint:

\(ClF_3\) has \(3\) bond pairs and \(2\) lone pairs, so its molecular geometry is T-shaped.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The objective is to determine the structural characteristics of chlorine trifluoride ($ClF_3$), an interhalogen compound. We need to identify its molecular geometry and the number of lone pairs residing on the central chlorine atom using the VSEPR (Valence Shell Electron Pair Repulsion) theory. VSEPR theory states that electron pairs around a central atom arrange themselves to minimize repulsion, which dictates the shape of the molecule.
Step 2: Key Formula or Approach:
Calculate the Steric Number (SN):
$SN = \frac{1}{2} [V + M - C + A]$
$V = \text{Valence electrons of central atom}$
$M = \text{Number of monovalent surrounding atoms}$
$C, A = \text{Charge (if any)}$
Lone Pairs (LP) = SN - Bond Pairs (BP)
Step 3: Detailed Explanation:

Central Atom: Chlorine ($Cl$) is in group 17, so it has $7$ valence electrons ($V=7$).
Surrounding Atoms: There are $3$ monovalent Fluorine ($F$) atoms ($M=3$).
Calculation: $SN = \frac{1}{2}(7 + 3) = 5$.
Hybridization: $SN = 5$ corresponds to $sp^3d$ hybridization and a Trigonal Bipyramidal (TBP) electronic geometry.
Identifying Pairs: The number of bond pairs ($BP$) is $3$ (one for each $F$ atom). The number of lone pairs is $LP = SN - BP = 5 - 3 = 2$.
Molecular Geometry: In a TBP arrangement, lone pairs occupy equatorial positions to minimize repulsions with bond pairs. With two lone pairs in equatorial spots and three bond pairs (two axial, one equatorial), the atoms form a "T" shape.
Therefore, $ClF_3$ is T-shaped with two lone pairs on the $Cl$ atom.
Step 4: Final Answer:
The correct description of $ClF_3$ is T-shaped geometry with two lone pairs on the central $Cl$ atom.