1.

Silver forms ccp lattice and X-ray studies of its crystals show that the edge length of its unit cell is 408.6 pm. Calculate the density of silver (Atomic mass = 107.9 u).

Answer»

Solution : Since the lattice is ccp, the number of Ag atoms per unit cell (z) = 4
Molar mass of Ag `= 107.9 "g mol"^(-1)`
Edge length of (a) = 408.6 PM
Volume of cube = `(408.6)^3 xx 10^(-30) "CM"^3`
`d = (Z xx M)/(N_A xx a^3)`
`therefore d= (4 xx (107.9 "g mol"^(-1)))/((6.022 xx 10^(23) "atomsmol"^(-1)) xx (408.6)^3 xx 10^(-30) "cm"^3)`
`therefore d = 10.5 "g cm"^(-3).`


Discussion

No Comment Found