In solid KCl, which has the same solid state structure as NaCl (simple cubic unit cell), the distance between the ions is 314 pm. Calculate the length of the edge of the unit cell.

The edge length of the KCl unit cell is 314 pm.

Explanation:

In simple cubic unit cell the edge length of the unit cell id given by:

r = 0.5 a

r = radius pf the atom

a = edge length

We have:

Distance between the ions in KCl unit cell = d = 314 pm

And we know that:

d = 2r

d = 2 (0.5a)

d = 1.0a = a = 314 pm

So, this means that edge length of the KCl unit cell is 314 pm.