A metal has a fcc lattice.The edge length of the unit cell is `404` pm ,the density of the metal is `2.72g cm^(-3)` . The molar mass of the metal is `(N_(A)`, Avorgadro's constant `=6.02xx10^(23)mol^(-1))`

Options

A. 27g/m
B. 20g/m
C. 40g/m
D. 30g/m

Answer

A

Explanation

`d=(ZM)/(N_(A)a^(3))" "(Z=4" for fcc")`
`M=(dxxN_(A)xxa^(3))/(Z)`
`=([2.72" g "cm^(3)xx6.023x10^(23)mol^(-1)xx(404xx10^(-10)cm)^(3)])/(4)`
`M=27g//mol`