Question

Total number of voids in 0.5 mole of a compound which forms hexagonal close packed structure is ____________.

Options

• 6.022 × 10²³

• 9.033 × 10²³

• 12.044 × 10²³

• 3.011 × 10²³

Answer 1

Total number of voids in 0.5 mole of a compound which forms hexagonal close packed structure is 9.033 × 10²³.

Explanation:

Number of atoms in 1 mole of compound = 6.022 × 10²³

Number of atoms in 0.5 mole of compound = 0.5 × 6.022 × 10²³ = 3.011 × 10²³

For a hexagonal close packed structure,

Number of octahedral voids = number of atoms in close packaging

Therefore, the number of octahedral voids = 3.011 × 10²³

and Number of tetrahedral voids = 2 × number of atoms in close packaging

So, Number of tetrahedral voids = 2 × 3.011 × 10²³ = 6.022 × 10²³

Total number of voids = Tetrahedral void + octahedral void

= (6.022 + 3.011) × 10²³

= 9.033 × 10²³