Chemistry - Solid State Question with Solution | TestHub

Number of moles of the compound = $0.2\text{ mol}$

Number of atoms in the hcp structure = $0.2\times N_A$

$=0.2\times 6.022\times 10^{23}=1.2044\times 10^{23}$

In any close-packed structure, the number of octahedral voids is equal to the number of atoms constituting the lattice.

Number of octahedral voids = $1.204\times 10^{23}$

Answer: $1.204\times 10^{23}$