Question

A compound forms hcp structure. What is the number of tetrahedral voids formed in 0.8 mol of it.

• A. \(4.818\times 10^{23}\)
• B. \(9.635\times 10^{23}\)
• C. \(7.227\times 10^{23}\)
• D. \(2.410\times 10^{23}\)

Hint:

There are two tetrahedral voids per atom in hcp.

Answer 1

The Correct Option is B

Step 1: Void rule:
For $N$ atoms in a close-packed lattice there are $2N$ tetrahedral and $N$ octahedral voids.

Step 2: Find N:
$N = 0.8\times6.022\times10^{23} = 4.818\times10^{23}$.

Step 3: Voids:
$2N = 9.635\times10^{23}$, option (B).

Final Answer:
There are 9.635e23 tetrahedral voids. \[ \boxed{\text{(B) }9.635\times10^{23}} \]