NEET2013ChemistrySolid StateActual
Assertion: The presence of a large number of Schottky defects in NaCl lowers its density. Reason : In NaCl , there are approximately 10^6 Schottky pairs per cm ^3 at room temperature.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
Step-by-step solution
When an atom or an ion is missing from its normal lattice site, a lattice vacancy or defect is created, which is called Schottky defect. Due to missing density of crystal will be lowered.