Question

A compound $CuCl$ has face centered cubic structure. Its density is $3.4gc{m}^{-3}$. The length of unit cell is :

• A. $5.783\mathring{A}$
• B. $6.783\mathring{A}$
• C. $7.783\mathring{A}$
• D. $8.783\mathring{A}$

Answer 1

The correct option is A $5.783\mathring{A}$

$Z_{eff}=4;\rho =3.4g/c{m}^3;$ Molecular weight $=99;N_A=$ Avogadro Number $=6.02\times {10}^{23}$

$\rho =\frac{M_A\times Z_A}{N_A\times a^3}$

$a^3=\frac{99\times 4}{6.02\times {10}^{2}3\times 3.4}=19.34\times {10}^{-23}$

$a^3=193.4\times {10}^{-24}cm$

$a=5.783\mathring{A}$