Tungsten crystallizes in a body centred cubic lattice. Calculate the number of unit cells in 1.5 g of tungsten. Atomic mass of tungsten = `184mu`.

Explanation

Molar mass of tungsten = (W), 184 `"g mol"^(-1)`
Mass of 1 atom of W
`=M/(N_(A))=(184"g mol"^(-1))/(6.022xx10^(23)"mol"^(-1))`
For b.c.c. lattice, z = 2
`therefore` Mass of one unit cell of tunsten = `2xx30.55xx10^(-23)g=61.1xx10^(-23)g`
`therefore` Number of unit cells in 1.5 g of tunsten
`(1.5g)/(61.1xx10^(-23)g)=(1.5xx10^(23))/(61.1)`
`(150xx10^(21))/(61.1)=2.45xx10^(21)`