What is the number of octahedral and tetrahedral voids presents respectively in 0.25 mole of a substance…
What is the number of octahedral and tetrahedral voids presents respectively in 0.25 mole of a substance having hcp structure?
$3.011 \times 10^{23}, 1.50 \times 10^{23}$
$6.011 \times 10^{23}, 3.011 \times 10^{23}$
$3.011 \times 10^{23}, 6.022 \times 10^{23}$
$1.50 \times 10^{23}, 3.011 \times 10^{23}$
Solution
In HCP structure for each atom one octahedral void and two tetrahedral voids will be present.
No. Of atoms $=0.25 \times \mathrm{N}_{\mathrm{A}}=0.25 \times 6.022 \times 10^{23}$
No. of octahedral voids $=0.25 \mathrm{~N}_{\mathrm{A}}$ $=1.5 \times 10^{23}$
No. of tetrahedral voids $=2 \times 0.25 \times \mathrm{N}_{\mathrm{A}}$ $=3.011 \times 10^{23}$