JEE Main2012ChemistrySolid StateActual
Ammonium chloride crystallizes in a body centred cubic lattice with edge length of unit cell of 390 pm . If the size of chloride ion is 180 pm , the size of ammonium ion would be
Options
- A174 pm
- B158 pm
- C142 pm
- D126 pm
Correct answer
B. 158 pm
Step-by-step solution
For bcc structure aligned Interionic distance = & r⁺+r⁻= 3 2 a & (a= edge length ) aligned aligned & r_ NH ₄⁺ ⁺+r_ Cl ⁻ ⁻= 3 2 a & r_ NH ₄⁺ ⁺+180= 3 2 390 aligned r _ NH ₄⁺ ⁺=338 pm -180 pm =158 pm