Calculate the value of Avogadro's number from the following data:
Density of `NaCl = 2.165 g cm^(-3)`
Distance between `Na^(o+)` and `Cl^(Θ)` in `NaCl = 281` pm

Explanation

We know that `rho=(ZxxM)/(a^(3)xxN_(0)xx10^(-30))orN_(0)=(ZxxM)/(a^(3)xxrhoxx10^(-30))`
Edge length of `NaCl (a) = 2(r_(Na)^(+)+r_(Cl)^(-))=2xx281=562"pm"=562`
No. of atoms per unit cell (Z) =4
Density of NaCl `(rho)=2.165"g cm"^(-3)`
Gram molecular mass of NaCl(M) = `23+35.5=58.5"g mol"^(-1)`
`therefore" Avogadro's Nomber"(N_(0))=(4xx(58.5"g mol"^(-1)))/((562)^(3)(2.165"g mol"^(-3))xx(10^(-30)"cm"^(3)))=6.089xx10^(23)"mol"^(-1)`