Looking for classes? Ksquare Career Institute, Bengaluru →
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
Detailed Solution
In the NaCl structure the cations occupy octahedral voids of the close-packed anion lattice.
For a cation that just fits an octahedral void, the limiting radius ratio is $\frac{r_+}{r_-} = 0.414$
$r_- = \frac{r_+}{0.414} = \frac{100}{0.414}$
$r_- = 241.5$ pm
For a cation that just fits an octahedral void, the limiting radius ratio is $\frac{r_+}{r_-} = 0.414$
$r_- = \frac{r_+}{0.414} = \frac{100}{0.414}$
$r_- = 241.5$ pm