Question

Sodium has a bcc structure with nearest neighbour distance of 360 5.9 picometres calculate its density

Answer 1

Answer:

As we have bcc structure, nearest neighbour distance (d) is related to the edge length (a) as follows :

d =√3a/2

or a =2d/√3

= (2×365.9) ÷ 1.732

= 422.5 × 10^(-10) cm

for bcc structure , z = 2

for sodium M = 23 g/mol

Density ρ = (z × M) ÷ (a^3 × N(a))

= [2 × 23] ÷ [ { 422.5 × 10^(-10) }^3 × 6.02 × 10^23

Density = 1.51 g/cm3