Question

The number of atoms in 100g of an fcc crystal

Answer 1

To calc the no. of atoms in given face centered cubic crystals

let the density of compound =d

let the cell edge length=a

for fcc crystal z=4

therefore density (d)= Z*Molar Mass/[(a)3 *avagadro no.(NA)]

hence d= [(4*MOLAR MASS)/a3*NA]

Therefore Molar Mass =[a3*NA*d]/4

NO. OF MOLES =MASS IN GRAM/MOLAR MASS

=100*4/a3*NA*d

NO. OF ATOMS = MOLES* NA

=400/a3*d

=400/[(edge length)^3]* density

hope u understand the answer

thanks