PrayogX › Chemistry › Chemical Bonding and Molecular Structure

Shapes of SOCl2, XeOF4, ClF3, ClF5, XeF5+, SO3 2-, XeF3+ and SF4 by VSEPR: see-saw, T-shaped, trigonal planar and square pyramidal counts

Eight species on eight cards. For each, the lab counts the valence electrons on the central atom, subtracts those used in bonds and the charge, and finds the lone pairs and steric number. The electron domains are then relaxed on a sphere by mutual repulsion - first all alike into the ideal polyhedron, then with lone pairs pushing harder, every placement tried and the lowest energy kept - and each rotating 3-D model is named from the angles between its bonded atoms. The species drop into shape bins, the counts are matched to List-II and options A-D are tested. No prediction stage - input, run, watch, result.

Sub-topics covered

• Counting lone pairs on the central atom
• Steric number and electron geometry
• Lone-pair repulsion and equatorial placement
• Shapes with lone pairs: see-saw, T-shaped, square pyramidal, trigonal pyramidal
• Xenon and interhalogen species

What it teaches

• Lone pairs = (valence electrons - electrons used in bonds - charge)/2; F and Cl use 1 electron, O uses 2
• SF4: SN 5, 1 LP equatorial - see-saw
• ClF3 and XeF3+: SN 5, 2 LP equatorial - T-shaped
• XeOF4, ClF5 and XeF5+: SN 6, 1 LP - square pyramidal
• SOCl2 and SO3 2-: SN 4, 1 LP - trigonal pyramidal, so no species is trigonal planar
• Counts 1, 2, 0, 3 give P1 Q2 R5 S3 - option A

Simulation ID

• ADV-2026-P1-CHE-Q14 · revision 1

See this simulation in the library →  ·  open the simulation file on its own