CsBr has a (bcc) arrangement and its unit cell edge length is 400 pm. Calculate the interionic distance in CsCl [CBSE 1993]

(1) 346.4 pm

(2) 643 pm

(3) 66.31 pm

(4) 431.5 pm

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The first order reflection (n = 1) from a crystal of the X-ray from a copper anode tube $\left(\lambda =0.154nm\right)$ occurs at an angle of 16.3°. What is the distance between the set of planes causing the diffraction.

(1) $0.374nm$

(2) $0.561\text{\hspace{0.17em}}nm$

(3) $0.274nm$

(4) $0.395\text{\hspace{0.17em}}nm$

Concept Questions :-

Introduction and Type of Crystal System
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The diffraction of barium with X-radiation of wavelength 2.29Å gives a first – order reflection at 30°. What is the distance between the diffracted planes.

(1) 3.29 Å

(2) 4.39 Å

(3) 2.29 Å

(4) 6.29 Å

Concept Questions :-

Introduction and Type of Crystal System
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

When an electron in an excited Mo atom falls from L to the K shell, an X-ray is emitted. These X-rays are diffracted at angle of $7{.75}^{o}$ by planes with a separation of 2.64Å. What is the difference in energy between K-shell and L-shell in Mo assuming a first-order diffraction. $\left(\mathrm{sin}7{.75}^{o}=0.1349\right)$

(1) 36.88 $×\text{\hspace{0.17em}}{10}^{-15}J$

(2) $27.88×{10}^{-16}J$

(3) 63.88 $×{10}^{-17}J$

(4) $64.88×{10}^{-16}J$

Concept Questions :-

Introduction and Type of Crystal System
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Which is the incorrect statement?

(a) FeO0.98 has non-stoichiometric metal deficiency defect

(b) Density decreases in case of crystals with Schottky's defect

(c) NaCI(s) is insulator, silicon is semiconductor, silver is conductor, quartz is piezoelectric crystal

(d) Frenkel defect is favoured in those ionic compounds in which sizes of cation and anions are almost equal

Concept Questions :-

Imperfections in Solids
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion (Ca2+) and fluoride ion (F-) are

(a) 4 and 2                   (b) 6 and 6

(c) 8 and 4                   (d) 4 and 8

Concept Questions :-

Introduction and Type of Crystal System
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Lithium has a bcc structure. Its density is 530 kg m-3 and its atomic mass is 6.94 gmol-1. Calculate the edge length of a unit cell of lithium metal.

(NA=6.02 x1023 mol-1)

(a) 352 pm
(b) 527 pm
(c) 264 pm
(d) 154 pm

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ionic radii of A+ and B- ions are 0.98 x 10-10 m and 1.81 x10-10 m.  The coordination number of each ion in AB is.

(a) 4

(b) 8

(c) 2

(d) 6

Concept Questions :-

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A given metal crystallises out with a cubic structure having edge length of 361 pm. If there are four metal atoms in one unit cell, what is the radius of one atom ?

(a) 40 pm

(b) 127 pm

(c) 80 pm

(d) 108 pm

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The correct statement regarding defects in the crystalline solid is

(a) Schottky defects have no effect on the density of crystalline solids

(b) Frenkel defects decreases the density of crystalline solids

(c) Frenkel defcct is a dislocation defect

(d) Frenkel defect is found in halides of alkaline metals

Concept Questions :-

Imperfections in Solids