Question

$\text{CuCl}$ has a zinc blende structure. Its density is $3.4$ g cm${}^{-3}$. The length of its unit cell edge (in pm) is:

Answer 1

Zinc blende (ZnS) has FCC or CCP structure and as CuCl has a similar structure, it means CuCl is also FCC.

Formula for Density $=\rho =\frac{ZM}{N_0{a}^3}$

Now by putting values, we get $3.4=\frac{3\times 99}{(6.022\times {10}^{23})\times (a{)}^3}⟹a=578$ pm

The length of its unit cell edge is 578 pm