Question

Identify the sets containing isostructural molecules from the following options: 
i: \({SiF}_4\), \({CCl}_4\) 
ii: \({NF}_3\), \({XeO}_3\) 
iii: \({BeCl}_2\), \({HgCl}_2\) 
iv: \({SF}_4\), \({XeF}_4\)

• A. i, ii, iii only
• B. ii and iii only
• C. i, iii, iv only
• D. ii and iv only

Hint:

Isostructural molecules not only share the same number of electron domains but also the same distribution between bonding and lone pairs, leading to similar spatial geometries.

Answer 1

The Correct Option is A

Step 1: Analyze the molecular geometries. 
Set i: Both molecules are tetrahedral, sharing identical electron pair geometries. 
Set ii: Both molecules have a pyramidal structure, albeit \(<NF_3>\) with bonding pairs and \(<XeO_3>\) with lone pairs affecting the structure. 
Set iii: Both are linear, having the simplest geometric arrangement. 
Step 2: Comparison with Set iv. Set iv does not contain isostructural molecules due to the different spatial arrangements (\(<SF_4>\) see-saw vs. \(<XeF_4>\) square planar).