Question

an element occurs in body centered cubic structure it has a cell edge of 250pm calculate it's molar mass if it's density is 8g/cm^3

Answer 1

so the molar mass is 37.64g

Answer 2

Answer: Molar mass is  $37.6 g/mol$

Explanation: Density of the crystal lattice is given by the formula:

$\rho=\frac{Z\times M}{N_A\times a^3}$

where,

Z = number of atoms in crystal lattice

M = Molar mass

a = Edge length of the crystal

Z = 2 (For bcc)

a = 250 pm = $250\times 10^{-10}cm$

Putting values in above equation, we get:

$8gcm^{-3}=\frac{2\times M}{6.022\times 10^{23}\times (250\times 10^{-10}cm)^3}$

$M=37.6g/mol$