In a solid, a tom M occupies ccp lattice and 1/3rd of tetrahedral voids are occupied by atom N. Find the formula of solid formed by M and N.
M3N2
M2N3
M4N3
M3N4
Assertion : The presence of a large number of Schottky defects in NaCl lowers its density.
Reason : In NaCl, there are approximately 106 Schottky pairs per cm3 at room temperature.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
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.
In tetragonal crystal system, which of following is not true?
All axial lengths and all axial angles are equal.
All three axial lengths are equal.
All three axial angles are equal.
Two axial angles are equal but the third is different.
In solid ice, oxygen atom is surrounded
tetrahedrally by 4 hydrogen atoms
octahedrally by 2 oxygen and 4 hydrogen atoms
tetrahedrally by 2 hydrogen and 2 oxygen atoms
octahedrally by 6 hydrogen atoms
Schottky defect is
vacancy of ions
delocalization of ions
interstitial vacancy of ions
vacancy of only cations
Assertion : bcc and hcp has same packing efficiency.
Reason : Both have same number of atoms per unit cell and same arrangement.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Due to Frenkel defect, density of the crystalline solid decreases.
Reason : In Frenkel defect, cation or anion leaves the crystal.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Schottky defect in crystals is observed when
unequal number cations and anions are missing from the lattice
equal number of cations and anions are missing from the lattice
an ion leaves its normal site and occupies an interstitial site
density of the crystal is increased.