StemCET Logo

Chemistry Question 53 – JEE-MAIN 2026

SF4 is isostructural with :

To determine if molecules are isostructural, compare their molecular geometries, which are derived from the VSEPR theory.

Step 1: Determine the molecular geometry of SF4.✦ Active

The central atom in SF4 is Sulfur (S), which has 6 valence electrons. It forms 4 single bonds with Fluorine (F) atoms, using 4 electrons. Remaining electrons = 64=2 electrons, which form 1 lone pair. Steric number = (number of bond pairs) + (number of lone pairs) = 4+1=5. Hybridization is sp3d. Electron domain geometry is trigonal bipyramidal. Molecular geometry (shape) is **see-saw** (due to one lone pair occupying an equatorial position).

💡 Teacher's Secret Hint

Remember that lone pairs influence the molecular geometry by occupying space and causing repulsion.

Step 2: Determine the molecular geometry of each given option.○ Expand

A) BrF4: Br has 7 valence electrons + 4 from F + 1 for negative charge = 12 electrons. 4 bond pairs, 2 lone pairs. Steric number = 4+2=6. Hybridization sp3d2. Shape: Square planar. (Not see-saw) B) CH4: C has 4 valence electrons + 4 from H = 8 electrons. 4 bond pairs, 0 lone pairs. Steric number = 4+0=4. Hybridization sp3. Shape: Tetrahedral. (Not see-saw) C) IF4: I has 7 valence electrons + 4 from F - 1 for positive charge = 10 electrons. 4 bond pairs, 1 lone pair. Steric number = 4+1=5. Hybridization sp3d. Shape: **See-saw**. (Isostructural with SF4) D) XeF4: Xe has 8 valence electrons + 4 from F = 12 electrons. 4 bond pairs, 2 lone pairs. Steric number = 4+2=6. Hybridization sp3d2. Shape: Square planar. (Not see-saw) E) XeO2F2: Xe has 8 valence electrons. 2 F atoms form single bonds (2 electrons). 2 O atoms form double bonds (4 electrons). Total bonding electrons = 2+4=6. Remaining electrons = 86=2, forming 1 lone pair. 4 bond domains (2 single, 2 double), 1 lone pair. Steric number = 4+1=5. Hybridization sp3d. Shape: **See-saw**. (Isostructural with SF4)

💡 Teacher's Secret Hint

For molecules with multiple bonds (like XeO2F2), count each multiple bond as one electron domain for steric number calculation.

Step 3: Identify the options with the same molecular geometry as SF4.○ Expand

Both IF4 (Option C) and XeO2F2 (Option E) have a see-saw molecular geometry, which is the same as SF4. Therefore, SF4 is isostructural with IF4 and XeO2F2. Comparing this with the given choices, "C and E Only" is the correct option.

💡 Teacher's Secret Hint

Isostructural means having the same molecular geometry and hybridization, which implies the same number of bond pairs and lone pairs around the central atom.

✦ STEM Console utilizes AI models to generate step-by-step explanations and math clues. AI can make mistakes.