At `100^(@)C`, copper (Cu) has FCC unit cell structure will cell edge length of `x Å`. What is the approximate density of Cu (in g `cm^(-3)`) at this temperature? [Atomic mass of Cu = 63.55 u]

Options

A. `105/(x^3)`
B. `(211)/(x^3)`
C. `(205)/(x^3)`
D. `(422)/(x^3)`

Answer

D

Explanation

`d = (Z xx M)/(a^3 xx N_A)`
`= (4 xx 63.55)/((x xx 10^(-8) cm)^(3) xx 6.022 xx 10^(23))`
`= 422/(x^3)`