Tag: imperfections in solids

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Multiple choice imperfections in solids solid state the solid state chemistry

(i) Frenkel defect create a vacancy defect at its original site and an interstitial defect at its new position.
(ii) Frenkel defect is stoichiometric point defect.
(iii) Frenkel defect is also called dislocation defect.
(iv) Silver halide shows Frenkel defect 
Select the correct statements :

  1. $(ii),(iii),(iv)$ only
  2. $(i),(ii),(iii)$ only
  3. $(i),(ii),(iii),(iv)$
  4. $(i),(ii),(iv)$ only
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

All statements are correct: Frenkel involves vacancy and interstitial sites, is stoichiometric, is called a dislocation defect, and is common in silver halides.

Multiple choice imperfections in solids solid state the solid state chemistry

$NaCl$ shows Schottky defects and $AgCl$ Frenkel defects. Their electrical conductivity is due to ________.

  1. motion of ions and not the motion of electrons

  2. notion of electrons and not the motion of ions
  3. lower coordination number of $NaCl$
  4. higher coordination number of $AgCl$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In ionic solids like NaCl and AgCl, electrical conductivity is primarily due to the migration of ions through vacancies or interstitial sites, not the movement of electrons.

Multiple choice imperfections in solids solid state the solid state chemistry

Metallic or non-stoichiometric (or interstitial) hydrides are formed by:

  1. Many d-block and f-block elements.

  2. Many s-block elements

  3. Many p-block elements

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metallic or interstitial hydrides are typically formed by d-block and f-block transition metals where hydrogen occupies interstitial sites in the metal lattice.

Multiple choice imperfections in solids solid state the solid state chemistry

Calculate the dencity of NaCl type ionic solid AB($M _{w}$=60) in $gm/CM^{3}$ if shortest distance between two nearest neighbours is 100 pm &solid having $20\%$ schottky defect$(N _{A}=6\times10^{23}$)

  1. 10

  2. 20

  3. 30

  4. 40
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice imperfections in solids solid state the solid state chemistry

When NaCl is doped with ${ 10 }^{ -3 }$ mole % of Sr${ Cl } _{ 2 }$, what is the number of cationic vacancies?

  1. ${ 10 }^{ -5 }\times { N } _{ A }$
  2. ${ 10 }^{ -7 }\times { N } _{ A }$
  3. 6.022$\times{ 10 }^{8 }{ N } _{ A }$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice imperfections in solids solid state the solid state chemistry

The composition of a sample of iron oxide is $Fe _{0.93}O _{1.0}$. What percentage of iron is present in the form of Fe(III)?

  1. $5.053$
  2. $10.053$
  3. $15.053$

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the percentage amount of Fe(III) be x and the amount of Fe(II) be $1-x$. Hence,  
$3x+2(1-x) = 2/0.93 = 2.15053$
On solving, we get, $x = 0.15053$
So, % of Fe(III) = 15.053

Multiple choice imperfections in solids solid state the solid state chemistry

The defect observed in solid substances having low coordination number is

  1. Schottky

  2. Frenkel

  3. Vacancy

  4. All of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Frenkel defect is typically observed in ionic solids where there is a large difference in size between the cation and anion, leading to a low coordination number. In this defect, smaller ions (usually cations) leave their normal lattice sites and occupy interstitial sites. Schottky defect is found in ionic solids with high coordination numbers where ions of similar sizes are missing.

Multiple choice imperfections in solids solid state the solid state chemistry

If $100$ moles of NaCI are doped with ${10^{ - 3}}$ moles of $Sr{C _2}$ what is the concentration of cation vacancies?

  1. $6.02 \times {10^{18}}mo{l^{ - 1}}$
  2. $12.04 \times {10^{18}}mo{l^{ - 1}}$
  3. $3.01 \times {10^{18}}mo{l^{ - 1}}$
  4. $12.04 \times {10^{20}}mo{l^{ - 1}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

10^-3 moles of SrCl2 in 100 moles of NaCl means 10^-5 moles of SrCl2 per mole of NaCl. This creates 10^-5 * 6.02 x 10^23 = 6.02 x 10^18 vacancies per mole.

Multiple choice imperfections in solids solid state the solid state chemistry

According to recent studies which of the following interstitial hydrides have simi-lattices that of their parent metals

  1. $La, Yb, W$
  2. $Yb, W, V$
  3. $V, I, a$
  4. $N, Pd, Ce, Ac$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

La, Yb, and W are known to form interstitial hydrides where the metal lattice remains essentially unchanged.

Multiple choice imperfections in solids solid state the solid state chemistry

Which of the following is an interstitial compound?

  1. $ PdCl _2 $
  2. $ NH _3 $
  3. $ZnO$
  4. $TiH$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An interstitial compound is a compound that is formed when an atom with a small enough radius sits in an interstitial hole in a metal lattice.  examples of small atoms are boron, carbon and nitrogen.  these compounds play important role in industries. Examples: TiH, Fe3H and Mn4N