Question

the edge length of rock salt type unit is 700 pm. if the radius of anion is 230 pm. then the radius of cation is​

Answer 1

Given:

The edge length of rock salt type unit is 700 pm. The radius of anion is 230 pm.

To find:

Radius of cation ?

Calculation:

We know that NaCl type of lattice shows FCC (face centres cubic) form. Now, the ionic ratio can be written as:

$\dfrac{ r_{ + }}{ r_{ - } } = 0.414$

$\implies \dfrac{ r_{ + }}{230} = 0.414$

$\implies r_{ + } = 0.414 \times 230$

$\implies r_{ + } = 95.22 \: pm$

So, the approximate radius of cation will be 95.22 pm.

• Note that , in this kind of questions, we do not need the "Edge Length" value in calculation.

Hope It Helps.

Answer 2

Answer:

radius of anion +radius of cation =a/2

so answer is 120.