A unit cell of sodium chloride has four formula units. The edge length of the unit cell is 0.564 nm.What is the density of sodium chloride ?

Explanation

Edge length of unit cell a = 0.564 nm
or `a = 0.564xx10^(-9)m`
Volume of unit cell `= a^(3)=(5.64xx10^(-8)cm)^(3)`
As we know,
The density `(rho)` of the unit cell
`= (n.M_(m))/(N_(o)xx a^(3))`
where, n = number of molecule in one unit cell.
`M_(m)=` Molar mass
`N_(o)` = Avogadro.s No.
`rho = (4xx58.5)/(6.023xx10^(23)xx(5.64xx10^(-8))^(3))=2.16 gm//cm^(3)`.