How many unit cell are present in a cubic-shaped ideal crystal of `NaCl` of mass `1.0 g`?

Options

A. `2.5 xx 10^(21)` unit cell
B. `5.14 xx 10^(21)` unit cell
C. `1.28 xx 10^(21)` unit cell
D. `1.71 xx 10^(21)` unit cell

Answer

a

Explanation

`(1)/(58.5) xx 6.023 xx 10^(23) = 1.029 xx 10^(22)`
A unit cell contacts `4 Na^(+)` ion and 4 CI ions
`(1.029 xx 10^(22))/(4) = 2.57 xx 10^(21) `unit cell