Question

Find the total number of tetrahedral and octahedral voids formed in 1 mole of a compound forming hcp structure.

Options

• 1.204 × 10²⁴

• 1.807 × 10²⁴

• 2.402 × 10²⁴

• 3.012 × 10²⁴

Answer 1

1.807 × 10²⁴

Explanation:

Number of atoms in 1 mol
= 6.022 × 10²³ atoms
Number of octahedral voids
= Number of atoms
= 6.022 × 10²³ = 0.6022 × 10²⁴
Number of tetrahedral voids 
= 2 × Number of atoms
= 2 × 6.022 × 10²³
= 1.2044 × 10²⁴
Total number of tetrahedral and octahedral
\[\mathrm{voids}=1.2044\times10^{24}+0.6022\times10^{24}=1.8066\times10^{24}\approx1.807\times10^{24}\]