Question

Total number or voids in $0.5$ mole or compound forming hexagonal closed packed structure are

• A. $6.022 \times 10^{23}$
• B. $3.011\times 10^{23}$
• C. $9.033\times 10^{23}$
• D. $4.516\times 10^{23}$

Answer 1

The Correct Option is C

In hexagonal close packed structure, there is 6 atoms per unit cell. $\therefore$ Number of octahedral voids $=6$ $\therefore$ Number of tetrahedral voids $=2 \times 6=12$ Total number of voids $=6+12=18$ $\therefore$ Total number of voids per atom $=\frac{18}{6}$ $= 3$ $\because$ In $1$ mole compound the total number of voids $=3 \times 6.023 \times 10^{23}$ $\therefore$ In $0.5$ mole compound, the total number of voids $=3 \times 0.5 \times 6.023 \times 10^{23}$ $=9.034 \times 10^{23}$