Question

calculate the no. of unit cells in 8.1 g of aluminium if it crystallises in a fcc structure (atomic no. of Al=27)

Answer 1

Hey !!

n = given mass/molar mass

    = $\frac{8.1}{27} mol$

Number of atoms = 8.1/27 × 6.022 ×× 10²³

Number of atoms in one unit cell = 4 (fcc)

Number of unit cell = [8.1/27 × 6.022 × 10²³]

    FINAL RESULT = 4.5 × 10²²

GOOD LUCK !!