Question

A compound is formed by three elements A ,B and C . Atoms of element B form hcp lattice . One eighth of tetrahedral void occupied by atoms of element A and One half of octahedral void occupied by atoms of element B . Formula of the compound is

Answer 1

Answer:

Given that, atoms of B forms hcp lattice. So, the atoms at corners are shared by 6 unit cells. So, its contribution is

6

1

; Face centered atoms contribute

2

1

and middle layer atoms contribute 1 each.

So, effective number of atoms in unit cell =

6

1

×12+

2

1

×2+1×3

=2+1+3=6

Number of tetrahedral voids =2× Number of atoms forming the lattice.

=2×6=12

So, number of atoms of A=

3

2

×12=8

Number of atoms of B=6

So, A:B⇒A:B

8:6 4:3

So, formula is A

4

B

3