Imperfections in solids - class-XII
Description: imperfections in solids | |
Number of Questions: 85 | |
Created by: Muni Gupte | |
Tags: solid state chemistry the solid state |
What type of stoichiometric defect is shown by $ZnS$?
Silver halides generally show ?
Assertion: In any ionic solid $[MX]$ with schottky defects, the numbers of positive and negative ions are same.
Reason: Equal number of cation and anion vacancies are present.
Which of the following defects is also known as dislocation defect?
Fill in the blanks by choosing an appropriate option. A sample of ferrous oxide has actual formula $Fe {0.93}O _{1.00}.$ In this sample __(i) fraction of metal ions are $Fe^+$ ions. ____(ii) type of non-stoichiometric defect is present in this sample.
Green $Cr^{3+}$ changes to yellow ${ Cro } _{ 4 }^{ 2- }$ on boiling with
The type of defect in $Nacl$ crystal will be -
If 1 mole of NaCl is doped with $10^{-3}$ mole of $SrCl _2$. What is the number of cationic vacancies per mole of NaCl ?
An excess of potassium ions makes KCl crystals appear violet or Lilac in colour since
If $NaCl$ is doped with $10^{-3}$ mol$\%$ of $SrCl _2$, the concentration of cation vacancies will be:
$KBr$ shows, which of the following defects?
In a non-stochiometric sample of cuprons sulphide, with the composition $Cu _{1.8}$, cupric ions are also present in the lattice. The mole % of $Cu^{2+}$ present in the copper content of the crystal is:
If $NaCl$ is doped with ${ 10 }^{ -4 }mol$% of ${ SrCl } _{ 2 }$, the concentration of cation vacancies will be: $\left( { N } _{ A }=6.02\times { 10 }^{ 23 }{ mol }^{ -1 } \right) $:
The mineral hawleyite, one form of $CdS$, crystallizes in one of the cubic lattices , with edge length 5.87 A The density of hawleyite is $ 4.63 g cm^{-3} $
In which cubic lattice does hawleyite crystallizes?
Which is correct statement?
(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 :
$NaCl$ shows Schottky defects and $AgCl$ Frenkel defects. Their electrical conductivity is due to ________.
Metallic or non-stoichiometric (or interstitial) hydrides are formed by:
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$(N _{A}=6\times10^{23}$)
When NaCl is doped with ${ 10 }^{ -3 }$ mole % of Sr${ Cl } _{ 2 }$, what is the number of cationic vacancies?
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)?
The defect observed in solid substances having low coordination number is
If $100$ moles of NaCI are doped with ${10^{ - 3}}$ moles of $Sr{C _2}$ what is the concentration of cation vacancies?
According to recent studies which of the following interstitial hydrides have simi-lattices that of their parent metals
Which of the following is an interstitial compound?
Which of the following defects decrease the density?
Frenkel defect is also known as
Iron (II) oxide is written as $\overline{FeO}$. What does it mean?
Formula of metal oxide with metal deficiency defect in its crystal is $A _{0.8}O$. The crystal contains $A^{2+}$ and $A^{3+}$ ions. The fraction of metal existing as $A^{2+}$ ions in the crystal is
The non-stoichiometric compound, titanium monoxide has a continuous range of composition from $Ti _{0.75}O$ to $TiO _{0.69}$ Which of the following is/are the correct regarding the possible composition of the compound ? $[Ti=48]$
Frenkel defect is noticed in
Which of the following defect, if present, lowers the density of the crystal?
The schottky defect appears in
The only incorrect effect on density by the given defect in solids is
The intrinsic or thermodynamic defect is
Give the correct order of initials T(true) or F(False) for following statements:
I. In an anti-fluorite structure, anions form FCC and cations occupy all the tetrahedral voids
II. If the radius of cation and anion is $20$ and $95$ pm, then the coordination number of the cation is the crystal is $4$.
III. An atom or ion is transferred from a lattice site to an interstitial position in Frenkel defect.
IV. The density of crystal always increases due to substitutional impurity defect.
Which of the following defects in the crystals may lower the density?
Which kind of defect is introduced by doping in silicon crystal?
Which of the following may have Frenkel defect?
Which of the following statement(s) is/are incorrect regarding the defects in solids?
The correct statement(s) regarding defects in solid is (are)
Missing of one cation and one anion from the crystal lattice is called
In a crystal, pair of ions are missing from normal sites. This is an example of which defect?
Which of the following crystals does not exhibit Frenkel defect?
The correct statement(s) regarding defects in solids is(are):
Scotty defect is observed in____________.
Non-stoichiometric compounds is/are :
Assertion: Frenkel defects are shown by $AgX$.
Reason: $Ag^+$ ions have small size.
The compounds having the general molecular formula $A^{2+ }Fe _{2.047}$are called Ferrites.
There are N atoms in a crystal with $N _1$ interstitial positions in its structure. If there are n Frenkel defects in the crystal, then n is equal to :
Which of the following statements regarding defects in solids is/are correct?
Give the correct order of initials T (true) or F (False) for following statements:
I. In an anti-fluorite structure, anions form FCC lattice and cations occupy all tetrahedral voids.
II. If the radius of cations and anions are $0.2\ \mathring A$ and $0.95\ \mathring A$, then co-ordination number of cation in the crystal is $4$.
III. An ion is transferred from a lattice site to an interstitial position in Frenkel defect.
IV. Density of crystal always increases due to substitutional impurity defect.
Frenkel defect is generally observed in___________.
Select the correct statement regarding F-centre.
Frenkel defect is found in crystals in which the radius ratio is:
An ionic solid has some point defect but its experimental density is equal to its theoretical density. The type of defect is:
Ionic solids with Schottky defects contain in their structure
In a solid lattice, the cation has left a lattice site and is located at an interstitial position. The lattice defect is known as____________.
Schottky defect defines imperfection in the lattice structure of :
Schottky defect is noticed in:
What type of crystal defect is indicated in the diagram below?
$Na^{+}$ | $Cl^{-}$ | $Na^{+}$ | $Cl^{-}$ | $Na^{+}$ | $Cl^{-}$ |
---|---|---|---|---|---|
$Cl^{-}$ | $Cl^{-}$ | $Na^{+}$ | $Na^{+}$ | ||
$Na^{+}$ | $Cl^{-}$ | $Cl^{-}$ | $Na^{+}$ | $Cl^{-}$ | |
$Cl^{-}$ | $Na^{+}$ | $Cl^{-}$ | $Na^{+}$ | $Na^{+}$ |
Which of the following is/are correct about the point defects?
A solid solution of $CdBr _{2}$ in $AgBr$ contains:
Which of the following exhibit Frenkel defect?
Which of the following defect is seen in $FeO ?$
Which kind of defect is shown by the given crystal?
${ K }^{ + }$ ${ Cl }^{ - }$ ${ K }^{ + }$ ${ Cl }^{ - }$ ${ K }^{ + }$ ${ Cl }^{ - }$
${ Cl }^{ - }$ $\Box $ ${ Cl }^{ - }$ ${ K }^{ + }$ $\Box $ ${ K }^{ + }$
${ K }^{ + }$ ${ Cl }^{ - }$ $\Box $ ${ Cl }^{ - }$ ${ K }^{ + }$ ${ Cl }^{ - }$
${ Cl }^{ - }$ ${ K }^{ + }$ ${ Cl }^{ - }$ ${ K }^{ + }$ $\Box $ ${ K }^{ + }$
The appearance of colour in solid alkali metal halides is generally due to:
How many defects exists in the arrangement of constituent particles of $7.45\ g$ $KCl$?
$[k=39,Cl=35.5gm/mole]$
Select the incorrect statement :
Which of the following defect is seen in $FeO$?
In a crystal, at $827^{\circ}C$, one out of $10^{10}$ lattice site is found to be vacant, while in the same solid, one out of $2 \times 10^9$ lattice site is found to be vacant at $927^{\circ}C$. What is the enthalpy of vacancy formation in kJ/mol unit?
Calcium crystallizes in a face centred cubic unit cell with a $=0.556$ nm. Calculate the density if it contains:
(ii) $0.1\%$ Schottky defect
Statement 1: KCl is more likely to show schottky defect while Lil is more likely to show Frenkel defect.
Statement 2: Schottky defect is more likely in ionic solids in which cations and anions are of comparable size while Frenkel defect is more likely is which cations and anions have large differences in their ionic sizes.
Statement-I: Solids having more $F-$centres possess intense colours.
Statement-II: Excess of $Na^{+}$ in $NaCl$ solid having F-centres makes it appear to pink.
Which of the following statements are correct?
Which of the following statements is/are correct ?
A strong current of trivalent gaseous boron passed through a germanium crystal decreases the density of the crystal due to part replacement of germanium by boron and due to interstitial vacancies created by missing Ge atoms. In one such experiment, one gram of germanium is taken and the boron atoms are found to be $150$ ppm by weight when the density of the Ge crystal decreases by $4\%$. Calculate the percentage of missing vacancies due to germanium which are filled up by boron atoms. Atomic weight of Ge $= 72.6$ amu and $B = 11$ amu.
Crystals have 'vacant sites' or 'defects' in them. When light strikes a photographic silver bromide paper, silver atoms move in through these defects to:
The pink colour of lithium chloride crystal is due to: