Question

An element having atomic mass 107.9mol/1 has fcc unit cell. The edge length of unit cell is 408.6pm. Calculate the density of the unit cell.
[Given Na= 6.022× 10 power 23mol/1].​
give me answer fast plz.

Answer 1

Explanation:

Silver forms cubic close packing (ccp) , therefore the number of silver atoms per unit cell z=4

Molar mass of silver M=107.9gmol−1=107.9×10−3kgmol−1

Edge length of unit cell a=408.6pm=408.6×10−12

Density d=(z.M)/(a3.NA)

d=4×(107.9×10−3kgmol−1)/(408.6×10−12m)3(6.022×1023mol−1)

=10.5×103kgm−3

d=10.5gcm−3