Calculate the number of unit cells in 8.1 g of aluminium if it crystallises in face-centred cubic (fcc) structure. (Atomic mass of Al = 27`g*mol^(-1)`)

Explanation

Moles of aluminium = `(8.1)/(27) mol `
No. of atoms of Al in 8.1 g = `8.1/(27) xx 6.022 xx 10^(23)`
No. of atoms in one unit cell = 4(fcc)
No. of unit cells = `8.1/27 xx (6.022 xx 10^(23))/(4)`
`= 4.5 xx 10^(22)` .