AP EAMCET20225 Jul 2022Morning ShiftChemistrySolid StateActual
Which of the following statement is correct for fcc lattice?
Options
- AThere are equal number of octahedral and tetrahedral voids in a unit cell.
- BThe tetrahedral voids are present at the edge centers
- COctahedral voids are present at the body center and edge centers.
- DIts packing efficiency (PE) is higher than hcp lattice PE.
Correct answer
C. Octahedral voids are present at the body center and edge centers.
Step-by-step solution
(a) There are equal number of octahedral and tetrahedral voids in a unit cell for fcc lattice is incorrect statement. The number of octahedral and tetrahedral void in unit cell for fcc lattice is 4 and 8 respectively. (b) The tetrahedral voids are present at the edge centers is incorrect as they are present on each body diagonal, i.e. diagonal of cubic unit cell. (c) Octahedral voids are present at the body center and edge centers. Statement (c) is correct. (d) Its packing efficiency (PE) is higher than hcp lattice