Question

An element cyrstallises in a structure having a fcc unit cell of and edge 200 pm. Calculate its density if 200 g of this element contains `24xx 10^(23)` atoms.

Answer 1

Correct Answer - `4.166 g cm^(-3)`
Molar mass `=(200)/(24xx10^(23))xx6.023xx10^(23)=50.19 g "mol"^(-1)` for fcc, Z=4, `V=a^(3)=(200xx10^(-10))^(3)`
Apply density `=(ZM)/(N_(0)xxV)`