|Class 12 Chemistry The Solid State||Placing third layer over the second layer , Covering Octahed|
Placing third layer over the second layer : Covering Octahedral Voids
Question: A compound is formed by two elements M and N. The element N
forms ccp and atoms of M occupy 1/3rd of tetrahedral voids. What
is the formula of the compound?
Answer: The ccp lattice is made by the atoms of the element N.
Here, the Number of tetrahedral voids = 2 X number of particles of the elements 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
2 x 1/3 = 2/3rd of the number of atoms of N.
Therefore, the ratio M:N = 2/3 :1 = 2:3
Hence formula of the compound is M2N3.