Please be patient as the PDF generation may take upto a minute.

An element X (At. wt = 80 g/mol)  having F.C.C structure, calculate no. of unit cells in 8 gm of X.
(1) 0.4 x N${}_A$
(2) 0.1 x N${}_A$
(3) 4x N${}_A$
(4) none of these 

Molybdenum (At. wt= 96g mol${}^{-1}$) crystallizers as bcc crystal. lf density of crystal is  10.3 g/cm${}^3$,  then radius of Mo atom is (use N${}_A$ = 6 $\times$ 10${}^{23}$) : 
(1) 111 Pm
(2) 314 Pm
(3) 135.96 Pm
(4) none of these

The atomic radius of strontium (Sr) is 215 pm and it crystallizes with a cubic closest packing. Edge length of the cube is:
(1) 430 Pm
(2) 608.2 Pm
(3) 496.53 Pm
(4) none of these 

By X-ray diffraction it is found that nickel (at mass = 59 g mol${}^{-1}$), crystallizes with ccp. The edge length of the unit cell is 3.5 $\stackrel{0}{A}$. lf density of Ni crystal is 9.0 g/cm${}^3$. Then value of Avogadro's number from the data is :
(1) 6.05 $\times$ 10${}^{23}$
(2) 6.11 $\times$ 10${}^{23}$
(3) 6.02 $\times$ 10${}^{23}$
(4) 6.023 $\times$ 10${}^{23}$

Which one of the following schemes of ordering closed packed sheets of equal sized spheres do not generate closest packed lattice?
(1) ABCABC
(2) ABACABAC
(3) ABBAABBA
(4) ABCBCABCBC

ln a cubic unit cell, seven of the eight corners are occupied by atoms A and centres of Faces are occupied by atoms B. The general formula of the compound is :
(1) A₇B₆
(2) A₇B${}_{12}$
(3) A₇B${}_{24}$
(4) A${}_{24}$B₇

An alloy of copper, silver and gold is found to have copper constituting the ccp lattice .lf silver atoms occupy the edge centres and gold is present at body centre, the alloy will have the formula:
(1) Cu${}_4 A{g}_{2}Au$ 
(2) $C{u}_{4}A{g}_{4}Au$
(3) $C{u}_{4}A{g}_{3}Au$
(4) CuAgAu
 

Select the incorrect statement: 
(1) Stoichiometry of crystal remains uneffected due to Schottky defect
(2) Frenkel defect is usually shown by ionic compounds having low coordination number
(3) F-centres generation is responsible factor for imparting the colour to the crystal
(4) Density of crystal always increases due to substitutional impurity defect

ln diamond, carbon atom occupy fcc lattice points as well as alternate tetrahedral voids,
edge length of the unit cell is 356 pm, then diameter of carbon atom is:
(1) 77.07 pm
(2) 154.14 pm
(3) 251.7 pm
(4) 89 pm

When NaCI is dopped with 10${}^{-5}$ mole % of SrCl${}_2$, what is the no. of cationic vacancies?
(1) 10${}^{-5} \times N_A$
(2) ${10}^{-7} \times N_A$
(3) $2 \times {10}^{-7} N_A$
(4) $None of these$

The composition of a sample of Wustite is Fe${}_{0.93}$O. What is the percentage of iron present  in  Fe${}^{3+}$ in total iron?
(1) 15.05%
(2) 25%
(3) 35%
(4) 45%

A certain sample of cuprous sulphide is found to have composition Cu_1.8S because of
incorporation of Cu${}^{2+}$ ions in the lattice. What is the mole % of Cu${}^{2+}$ in total copper content in this crystal?
(1) 99.8% 
(2) 11.11%
(3) 88.88%
(4) None of these 

ln an atomic bcc, what fraction of edge is not covered by atoms?
(1) 0.32
(2) 0.16
(3) 0.134
(4) 0.268

An atomic solid crystallizes in a body centre cubic lattice and the inner surface of the atoms at the adjacent corner are separated by 60.3 Pm. lf the atomic weight of 
A is 48, then density of the solid , is nearly:
(1) 2.7 g/cc
(2) 5.07 g/cc
(3) 3.5 g/cc
(4) 1.75 g/cc
 

Sodium (Na = 23) crystallises in bcc arrangement with the interfacial separation between the atoms at the edge 53.6 pm. The density of sodium crystal is;
(1) 2.07 g/cc
(2) 2.46 g/cc
(3) 1.19 g/cc
(4) none of these 

If the anions (A) from hexagonal closest packing and cations (C) occupy only 2/3 octahedral voids in it, then the general formula of the compound is:
(1) CA
(2) CA₂
(3) C₂A₃
(4) C₃A₂

A body centered cubic lattice is made up of hollow spheres of B. Spheres of solid A are present in hollow spheres of B. Radius of A is half of radius of B. What is the ratio of total volume of spheres of B unoccupied by A in a unit cell and volume of unit cell?
(1) $\frac{7\sqrt{3\mathrm{\pi }}}{64}$
(2) $\frac{7\sqrt{3}}{128}$
(3) $\frac{7.\mathrm{\pi }}{24}$
(4) None of these

When heated above 916$°$C, iron changes its bcc crystalline form to fcc without the change in the radius of atom. The ratio of density of the crystal before heating and after heating is:
(1) 1.069
(2) 0.918
(3) 0.725
(4)1.231

TlAl(SO₄)₂.xH₂O is bcc with 'a'=1.22 nm. If the density of the solid is 2.32 g/cc, then the value of x is (Given : NA=6$\times$10²³; at. wt. : Tl=204, Al = 27, S=32).
(1) 2
(2) 4
(3) 47
(4) 70

The packing efficiency of a simple cubic crystal with an interstitial atom exactly fitting at the body center is:
(1) 0.48
(2) 0.52
(3) 0.73
(4) 0.91