Ncert Exercises & Solutions

1.15 A compound forms hexagonal close-packed structure. What is the total number of voids in 0.5 mol of it? How many of these are tetrahedral voids?

Number of close-packed particles = 0.5 × 6.022 × 10²³ = 3.011 × 10²³
Therefore, number of octahedral voids = 3.011 × 10²³
And, number of tetrahedral voids = 2 × 3.011 × 10²³ = 6.022 ×10²³
Therefore, total number of voids = 3.011 × 10²³ + 6.022 × 10²³ = 9.033 × 10²³