Question

Q4*) A compound?is formed by two elements M&N the element N forms CCP and atoms of M occupy 1/3rd of tetrahedral voids what is the formula of the compound

Answer 1

The ccplattice is formed by the atoms of the element N.

Here, the number of tetrahedral voids generated is equal to twice the number of atoms of the element N.

According to the question, the atoms of element M occupy 1/3rd of the tetrahedral voids.

Therefore, the number of atoms of M is equal to 2x1/3 = 2/3rd of the number of atoms of N.

Therefore, ratio of the number of atoms of M to that of N is M: N =2/3 :1 = 2 : 3

Thus, the formula of the compound is M2N3.

Another way to find the answer,
In CCP crystal
Number of N atoms (Z) = 4
Number of tetrahedral voids = 2Z = 8
Number of M atoms = 1/3rd of 8 = 8/3
N:M = 4: 8/3
Formula, = N12M8
or
N3M2