The density of `KCl` is `1.9893g cm^(-3)` and the length of a side unit cell is `6.29082Å` as determined by `X-`ray diffraction. Calculation the value of Avogadro's number.

Explanation

KCl has face-centred cubic structure, Hence, no. of atoms per unit cell, (Z)=4
Edge of the unit cell (a)=`6.09082xx10^8` cm
`rho=(ZxxM)/(a^3xxN_0) therefore 1.9893=(4xx74.5)/((6.29082xx10^(-8))^3xxN_0) "or " N_0=6.017 xx 10^23`