Calculate the value of Avogadro's number from the following data Density of `NaCl=2.165"g cm"^(-3)`. Distance between `Na^(+)andCl^(-)` in NaCl crystal = 281 pm.

Explanation

`"Edge length",a=2xx"Distance between"Na^(+)andCl^(-)`
`a=2xx281"pm"=562"pm"`
`=5.62xx10^(-8)"cm"`
`d=2.165"g cm"^(-3),z`
(f.c.c. lattice) = 4
M (Molar mass of NaCl)
`=23+35.5=58.5"g mol"^(-1)`
`N_(A)=(ZxxM)/(a^(3)xxd)`
`=(4xx52xx5"g mol"^(-1))/((5xx62xx10^(-8))^(3)"cm"^(3)xx2xx165"g cm"^(-3))`
`=(234.0"mol"^(-1))/(177.5xx10^(-24)xx2.165)`
`=(2340xx10^(23)"mol"^(-1))/(177.5xx2.165)`
= 6.09 `10^(23)"mol"^(-1)`