Q. A solid compound XY has NaCl structure. If the radius of the cation is 100 pm, the radius of the anion (Y⁻) will be
A) 241.5 pm
B) 165.7 pm
C) 275.1 pm
D) 322.5 pm
Explanation
[Solution from source] In the NaCl (octahedral) structure the limiting radius ratio r⁺/r⁻ = 0.414, so r⁻ = 100/0.414 ≈ 241.5 pm. Using 0.732 (the CsCl value) or 0.225 (tetrahedral) gives the other radii. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.