Question

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.​

Answer 1

Answer :

• Total number of voids = $\rm{9.033\times{}10^{23}}$
• Number of tetrahedral voids = $\rm{6.022\times{}10^{23}}$

Step-by-step explanation :

Given that,

• The compound forms hcp structure.

Also,

• An atom in hcp structure has three voids, one octahedral and the other two tetrahedral.

$\hrulefill$

Number of atoms in 0.5 mol =

$\implies\rm{0.5\times{}6.022\times{}10^{23}}$

$\implies\rm{3.011\times{}10^{23}}$

Now, we are provided that a total of three voids are present in an atom of hcp structure.

∴ Total number of voids present in $\rm{3.011\times{}10^{23}}$ atoms :-

$\implies\rm{3\times{}3.011\times{}10^{23}}$

$\implies\bold{9.033\times{}10^{23}}$

Again, we are given that two tetrahedral voids are present in an atom of hcp structure.

∴ Number of tetrahedral voids :-

$\implies\rm{2\times{}3.011\times{}10^{23}}$

$\implies\bold{6.022\times{}10^{23}.}$

Answer 2

Answer:

Tetrahedral voids are twice the no as of atoms in HCP. Therefore, 9.033×10^23 voids will be present in 0.5 mol of compound.