19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The correct statement regarding F-centre is
Schottky defect in crystals is observed when
Which defect causes decrease in the density of crystal
In a solid lattice the cation has left a lattice site and is located at an interstitial position, the lattice defect is
Which of the following defects are also called thermodynamic defects?
Which of the following compounds shows both Frenkel and Schottky defects [AMU 2010]
The maximum radius of sphere that can be fitted in the tetrahedral hole of cubic close packing of sphere of radius r is.
For an ionic crystal of the general formula AX and coordination number 6, the value of radius ratio will be
Zinc oxide loses oxygen on heating according to the reaction, heat ZnO Zn O 2e → It becomes yellow on heating because
If the value of ionic radius ratio c a r r is 0.52 in an ionic compound, the geometrical arrangement of ions in crystal is
If the radius of K⁺ and F– are 133 pm and 136 pm respectively, the distance between K⁺ and F– in KF is
The number of formula unit in unit cell of CsCl, type is
If ‘a’ stands for the edge length of the cubic systems: simple cubic, body centred cubic and face centred cubic, then the ratio of radii of the spheres in these system will be respectively. [CBSE AIPMT 2008]
The interionic distance for caesium chloride crystal will be
In A+ B– ionic compound, radii of A+and B– ions are 180 pm and 187 pm respectively. The crystal structure of this compound will be
Ferrous oxide has a cubic structure and each edge of the unit cell is 5.0 Å. Assuming density of the oxide as 4.0 g cm–3, then the number of Fe²⁺ and O₂– ions present in each unit cell will be
In NaCl lattice the radius ratio is Na Cl r r =
In NaCl lattice the coordination number of Cl– ion is
In CsCl structure, the coordination number of Cs⁺ is
Which of the following fcc structure contains cations in alternate tetrahedral voids ?
Total number of voids in 0.5 mole of a compound forming hexagonal closed packed structure are
AB crystallises in a body-centred cubic lattice with edge 'a' equal to 387 pm. The distance between two oppositely charged ions in the lattice is (CBSE AIPMT 2010)
Number of unit cells in 4 g of X (atomic mass = 40) which crystallises in bcc pattern is (NA = Avogadro's number) (OJEE 2010) (a) A 0.1N (c) A 2 0.1N x (b) A 0.1N (d) A N x
If in a crystal lattice of a compound, each corner of a cube is enjoyed by sodium, each edge of a cube has oxygen and centre of cube is enjoyed by tungsten (W), then give its formula [Guj. CET 2011]
In ABC packing if the number of atoms in the unit cell is n then the number of tetrahedral voids in the unit cell is equal to