JEE Chemistry 2025 Question with Solution

Given: The question asks about the correctness of two statements for $\text{ClF}_3$.

Find: Which option correctly identifies whether Statement I and Statement II are correct or incorrect.

For $\text{ClF}_3$, chlorine has $5$ electron pairs around the central atom: $3$ bond pairs and $2$ lone pairs. The electron-pair arrangement is trigonal bipyramidal.

In a trigonal bipyramidal arrangement, lone pairs prefer equatorial positions because this minimizes lone pair-bond pair repulsion. Axial positions experience greater repulsion than equatorial positions for lone pairs.

So, Statement I is correct because all three possible structures can be drawn for $\text{ClF}_3$.

Statement II says that structure III is most stable because the lone pairs are axial and therefore $\ell p - \beta p$ repulsion is minimum. This is incorrect, because lone pairs are more stable in equatorial positions, not axial positions.

Therefore, Statement I is correct but Statement II is incorrect. The correct option is B.

Given: Statements about the stability of structures of $\text{ClF}_3$.

Find: Evaluate both statements using lone pair position preference in $sp^3d$ hybridization.

The central atom Cl in $\text{ClF}_3$ has $7$ valence electrons. It forms $3$ bonds with fluorine atoms, leaving $2$ lone pairs on chlorine.

Thus, the steric number is

so the electron geometry is trigonal bipyramidal.

In trigonal bipyramidal geometry:

• an equatorial position has fewer $90^\circ$ interactions
• an axial position has more $90^\circ$ interactions

Since lone pairs repel more strongly, they occupy equatorial positions to reduce repulsion.

Hence the claim in Statement II that axial lone pairs give minimum $\ell p - \beta p$ repulsion is opposite to the actual rule. Therefore, Statement II is incorrect.

At the same time, the statement that all three possible structures can be drawn is accepted as correct in the given context. Hence Statement I is correct.

So the final conclusion is: Statement I is correct but Statement II is incorrect, therefore the answer is B.