Question

an fcc lattice has lattice parameter a=400 pm Calculate the molar volume of the lattice including all these empty space​

Answer 1

Answer:

Explanation:

edge length = a³ = (400)³pm

                                      = 64 * 10⁻²⁴ cm³

volume of NA unit cell = 64 * 10⁻²⁴ * 6.023 * 10²³

                                     = 38.4 cm³

since it is fcc lattice, no of atoms would be = 4

actually the formula is = d = z * m/ NA * a³  (where NA =Avogadro's constant)

so, m=d * NA * a³/z ( where z = no. of atoms in the given lattice)

hence, if we substitute all the values in the formula, we would obtain the answer

m =  38.4/4 = 9.6 mL