AP EAMCET201822 Apr 2018Evening ShiftChemistrySolid StateActual
A compound is formed by X and Y elements. Atoms of Y (anions) from hcp lattice. Atoms of X (cations) are in some octahedral holes. The formula of the compound is X Y₃ . What is the fraction of octahedral holes unoccupied by X ?
Options
- A1 2
- B2 3
- C3 4
- D1 5
Correct answer
B. 2 3
Step-by-step solution
Number of octahedral voids = Number of lattice point Given formula is X Y₃ means. three octahedral voids are filled against each lattice point (particle). 3 octahedral voids fill =1 full part of Y₃ . 1 octahedral voids fill = 1 3 part of Y₃ . Unoccupied fraction of voids =1- 1 3 = 2 3