NiO adopts the face-centered-cubic arrangement. Given that the density of NiO is 6.67 g/cm3, calculate the length of the edge of its unit cell (in pm).

Answer 1

density = Z x M / N_o x a³

density = 6.67 g/cm³

Z = 4

M = 74.6 g/mol

N_o = 6.02x10²³ atoms/mol

a = length in cm

6.67 g/cm³ = (4)(74.6) / (6.02x10²³)(a³)

a³ = 7.43x10^-23 cm³

a = 420 pm