An element with density `2.8g*cm^(-3)` forms a fcc unit cell with edge length `4xx10^(-8)`cm. Calculate the molar mass of the element. [Given: `N_(A)=6.022xx10^(23)mol^(-1)]

Explanation

Molar mass of an element forming cubic crystal structure can be calculated from the relation, `M=(rhoxxa^(3)xxN_(A))/Z`
For a fcc lattice Z = 4.
Therefore, `M=(2.8xx(4xx10^(-8))^(3)xx6.022xx10^(23))/4`
`=(2.8xx64xx6.022)/40~~26.98g*mol^(-1)`