Sodium crystallizes in a bcc unit cell. Calcuate the approximate number of unit cells in 9.2 g of sodium (Atomic mass of Na=23)

Answer

`1.2044 xx 10^(23)` unit cells

Explanation

1 mol of sodium = 23 g = `6.022 xx 10^(23)` atoms
No. of atoms present in 9.2 g of sodium
`= (6.022 xx 10^(23))/(23) xx 9.2 = 2.4088 xx 10^(23)`
A bcc unit cell contains 2 atoms,
`:. ` No. of unit cells present = `(2.4088 xx 10^(23))/(2)`
=`1.2044 xx 10^(23)`.