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

Answer

A

Explanation

No. of `Na^(+)Cl^(-)`units in one unit cell =4 Mass of 1 unit cell
`=(4(23+35.5))/(6.02times10^(23))g=((58.5times4)/(6.02times10^(23)))g`
No. of unit cells in 1 g
`=(6.02times10^(23))/(58.5times4)=602/(58.5times4)=10^(21)=2.57times10^(21)`