CBSE
The crystal system of a compound with unit cell dimensions , a = 0.387 , b = 0.387 and c = 0.504 run and = = 90° and = 120° is :
cubic
hexagonal
orthorhombic
rhombohedral
Tincture of iodine is :
aqueous solution of I2
solution of I2 in aqueous KI
alcoholic solution of I2
aqueous solution of KI
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
The Ca2+ and F- are located in CaF2 crystal respectively at face-centred cubic lattice points and in
tetrahedral voids
half of tetrahedral voids
octahedral voids
half of octahedral voids
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.
CsCl has bcc arrangement. Its unit cell edge length is 400 pm. Its inter-ionic distance is
400 pm
800 pm
100 pm
In bcc structure contribution of comer and central atom is
Assertion: Monoclinic sulphur is an example of monoclinic crystal system.
Reason: For a monoclinic system, ab c and a = 90°, 90°.
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.
Which of the following is an amorphous solid?
Iron
Graphite
Diamond
Glass
Which defect causes decrease in the density of crystal ?
Frenkel
Schottky
Interstitial
F-centre