The arrangement of X- ions around A+ ion in solid AX is given in the figure (not drawn to scale). If the radius of X- is 250 pm, the radius of A+ is

Question

The arrangement of X- ions around A+ ion in solid AX is given in the figure (not drawn to scale). If the radius of X- is 250 pm, the radius of A+ is (A) 104pm (B) 125pm (C) 183pm (D) 57pm

Tardigrade Admin · Accepted Answer

Given arrangement represents octahedral void and for this (r+ (cation)/r- (anion)) = 0.414 (r(A+)/r(X-)) = 0.414 r(A+) = 0.414 × r(X-) = 0.414 × 250pm = 103.5 pm ≈ 104 pm

Q. The arrangement of $X^{-}$ ions around $A^{+}$ ion in
solid $A X$ is given in the figure (not drawn to scale). If the
radius of $X^{-}$ is $250 p m$ , the radius of $A^{+}$ is

104pm

125pm

183pm

57pm

Given arrangement represents octahedral void and for this
$\frac{r _{+} ( c a t i o n )}{r _{-} ( ani o n )} = 0.414$
$\frac{r ( A ^{+} )}{r ( X ^{-} )} = 0.414$
$r (A^{+}) = 0.414 \times r (X^{-}) = 0.414 \times 250 p m$
$= 103.5 p m \approx 104 p m$

Q. The arrangement of X− ions around A+ ion in solid AX is given in the figure (not drawn to scale). If the radius of X− is 250pm, the radius of A+ is