NTA Abhyas JEE Main2020ChemistrySolid StatePractice
A crystalline solid is made of X, Y and Z. Atoms of X are present in ccp lattice; Y occupies all the octahedral voids and Z occupies all the tetrahedral voids. If all atoms along a body diagonal are removed then the formula of solid will be
Options
- AX 5 Y 4 Z 8
- BX 8 Y 4 Z 5
- CX 2 Y Z 2
- DX Y Z 2
Correct answer
A. X 5 Y 4 Z 8
Step-by-step solution
Number of X-atoms in unit cell = 4 Number of Y-atoms = 4 Number of Z atoms = 8 If atoms along one body diagonal are removed then 2 from corners X, 1 from body center Y and 2 neat two corners Z atoms will be absent. Effective number of atoms may be calculated as X = 4 - 2 × 1 8 = 15 4 Y = 4 - 1 = 3 Z = 8 - 2 = 6 Simplex ratio = X : Y : Z = 15 4 : 3 : 6 = 5 : 4 : 8 Simplest formula = X 5 Y 4 Z 8 .