Question

a solid compound XY has NaCl structure. If the radius of the cation is 100pm ,the radius of the anion (Y-) will be

Answer 1

Answer:

Nacl comes in octahedral .so radius ratio of Nacl is r+/r-=0.414

so, r+=100pm. 100/r-=0.414. r-=214.5

Answer 2

Answer:

The radius of anion Y⁻ is equal to 241.54pm.

Explanation:

For a given compound XY which has NaCl structure

We can say that

  X⁺ = Na⁺ while Na is present at octahedral voids in NaCl crystal

  Y⁻ = Cl⁻   which is present at the corners of the cubic crystal

Both Na⁺ and Cl⁻ has coordination number six

So  Radius ratio  $\frac{r^{+}}{r^{-}}=0.414$

Given the radius of cation = 100pm

                  $\frac{100}{r^{-}}=0.414\\\\ r^{-}=\frac{100}{0.414}\\ \\ r^{-}=241.54pm$

Therefore the radius of anion will be 241.54pm.