Solid State Test

Result

Solid State Test - 8

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
4 / -1

Which is the defect represented by the given figure

A
Schottky defect

B
Frenkel defect

C
Vacancy defect

D
Interstitial defect

Solution

In Frenkel defect, the smaller cation is dislocated from its normal position to an interstitial site.
Question 2
4 / -1

What is the effect of Frenkel defect on the density of ions solids?

A
The density of the crystal increases

B
The density of the crystal decreases

C
The density of the crystal remains unchanged

D
There is no relationship between density of a crystal and defect present in it

Solution

In Frenkel defect, ions get displaced from their original position and move to interstitial sites. Hence, there is no change in the density of the crystal.
Question 3
4 / -1

Alkali halides do not show Frenkel defect because

A
Cations and anions have almost equal size

B
There is a large difference in size of cations and anions

C
Cations and anions have low coordination number

D
Anions cannot be accommodated in voids

Solution

Frenkel defect is not shown by alkali metals because cations and anions have almost same size and cations cannot be accommodated in interstitial sites.
Question 4
4 / -1

What type of stoichiometric defect is shown by ZnS?

A
Schottky defect

B
Frenkel defect

C
Both Frenkel and Schottky defects

D
Non-stoichiometric defect

Solution

The stoichiometric defect shown by ZnS is Frenkel defect which is due to the large difference in the size of the ions, i.e. due to the small size of Zn²⁺.
Question 5
4 / -1

In Schottky defect,

A
An ion moves to interstitial position between the lattice points

B
Electrons are trapped in a lattice site

C
Some lattice sites are vacant

D
Some extra cations are present in interstitial spaces

Solution

In ionic crystals, the Schottky defect forms when oppositely charged ions leave their lattice sites, creating vacancies. These vacancies are formed in stoichiometric units, to maintain an overall neutral charge in the ionic solid.
Question 6
4 / -1

Which type of crystal defect is shown in the given figure?

A
Frenkel defect

B
Schottky defect

C
Interstitial defect

D
Cation excess defect

Solution

Equal number of cations and anions are missing from the crystal.
Question 7
4 / -1

Silver halides generally show

A
Schottky defect

B
Frenkel defect

C
Both Frenkel and Schottky defects

D
Cation excess defect

Solution

Silver halides generally show both Frenkel and Schottky defects.
Question 8
4 / -1

In the given crystal structure what should be the cation X which replaces Na⁺ to create a cation vacancy?

A
Sr²⁺

B
K⁺

C
LI⁺

D
Br^-

Solution

Each Sr²⁺ in the NaCl crystal replaces two Na⁺ ions. It occupies the site of one ion and the other remain vacant creating a cation vacancy.
Question 9
4 / -1

An electron trapped in an anion site in a crystal is called

A
F-centre

B
Frenkel defect

C
Schottky defe

D
Interstitial defect

Solution

F-centres are electron trapped anion site which are responsible for colour.
Question 10
4 / -1

In the following figure, the blank X is known as __________ and why?

A
Electron trap, because an electron is present here

B
Metal deficient centre, since negative charge is present here

C
F-centre, since it imparts colour to the crystal

D
F-centre, since it is responsible for positive charge on the crystal

Solution

The anionic sites occupied by the unpaired electrons are called F-centres from the German word Farbenzenter for colour centre.
Question 11
4 / -1

The anionic sites occupied by unpaired electrons are called F-centres or colour centres. They impart (X) colour to the crystals of NaCl. Excess of lithium makes LiCl crystals (Y) and excess of potassium makes KCl crystals (Z). (X), (Y) and (Z) are

A
Yellow, green and pink respectivelyf

B
Pink, yellow and violet (or lilac) respectively.

C
Yellow, pink and violet (or lilac) respectively.

D
Red, yellow and pink respectively

Solution

F-centres impart yellow colour to the crystal of NaCl when heated in an atmosphere of sodium vapour. Similarly, excess of lithium makes LiCl crystals pink and excess of potassium makes KCl violet(or lilac)
Question 12
4 / -1

Zinc oxide loses oxygen on heating according to the reaction,

It becomes yellow on heating because

A
Zn²⁺ ions and electrons move to interstitial sites and F-centres are create

B
Oxygen and electrons move out of the crystal and ions become yellow

C
Zn²⁺ again combine with oxygen to give yellow oxid

D
Zn²⁺ are replaced by oxygen

Solution

Zn²⁺ ions and electrons moves to interstitial sites and F-centres are created which impart yellow colour to ZnO.
Question 13
4 / -1

Which of the following will have metal deficiency defect?

A
NaCl

B
FeO

C
KCl

D
ZnO

Solution

FeO is mostly found with a composition of Fe_0.95O.(Ranges from Fe_0.93O - Fe_0.96O). In crystal of FeO, some Fe²⁺ cations are missing and the loss of positive charge is made up by the presence of the required number of Fe³⁺ ions.
Question 14
4 / -1

Experimentally it was found that a metal oxide has formula M_0.98O. Metal M, is present as M²⁺ and M³⁺ in its oxide. Fraction of the metal which exists as M³⁺ would be

A
5.08%

B
7.01%

C
4.08%

D
6.05%

Solution

Let the fraction o f metal which exists as M²⁺ be x. Then the fraction of metal as M²⁺ = (0.98 - x)
3x + 2( 0.98 - x) = 2
x + 1.96 = 2
x = 0.04
% of M³⁺ = 0.04/0.98 x 100
= 4.08%
Question 15
4 / -1

Mark the incorrect pair from the following.

A
Schottky defect- Equal number of cations and anions are missing

B
Frenkel defect - Dislocation of cation from its normal site to an interstitial site

C
Impurity defect- CdCl₂ in AgCl crystal to create cationic vacancy

D
Metal excess defect - Fe_0.93O

Solution

Fe_{0 93}O is a metal deficiency defect. In FeO, some Fe²⁺ ions are missing and the loss of positive charge is made up by Fe³⁺ ions.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Solid State Test - 8

Result

Solid State Test - 8

Score

-

Rank

-

SHARING IS CARING

Question 1

Schottky defect

Frenkel defect

Vacancy defect

Interstitial defect

Solution

Question 2

The density of the crystal increases

The density of the crystal decreases

The density of the crystal remains unchanged

There is no relationship between density of a crystal and defect present in it

Solution

Question 3

Cations and anions have almost equal size

There is a large difference in size of cations and anions

Cations and anions have low coordination number

Anions cannot be accommodated in voids

Solution

Question 4

Schottky defect

Frenkel defect

Both Frenkel and Schottky defects

Non-stoichiometric defect

Solution

Question 5

An ion moves to interstitial position between the lattice points

Electrons are trapped in a lattice site

Some lattice sites are vacant

Some extra cations are present in interstitial spaces

Solution

Question 6

Frenkel defect

Schottky defect

Interstitial defect

Cation excess defect

Solution

Question 7

Schottky defect

Frenkel defect

Both Frenkel and Schottky defects

Cation excess defect

Solution

Question 8

Sr2+

K+

LI+

Br-

Solution

Question 9

F-centre

Frenkel defect

Schottky defe

Interstitial defect

Solution

Question 10

Electron trap, because an electron is present here

Metal deficient centre, since negative charge is present here

F-centre, since it imparts colour to the crystal

F-centre, since it is responsible for positive charge on the crystal

Solution

Question 11

Yellow, green and pink respectivelyf

Pink, yellow and violet (or lilac) respectively.

Yellow, pink and violet (or lilac) respectively.

Red, yellow and pink respectively

Solution

Question 12

Zn2+ ions and electrons move to interstitial sites and F-centres are create

Oxygen and electrons move out of the crystal and ions become yellow

Zn2+ again combine with oxygen to give yellow oxid

Zn2+ are replaced by oxygen

Solution

Sr²⁺

K⁺

LI⁺

Br^-

Zn²⁺ ions and electrons move to interstitial sites and F-centres are create

Zn²⁺ again combine with oxygen to give yellow oxid

Zn²⁺ are replaced by oxygen

Impurity defect- CdCl₂ in AgCl crystal to create cationic vacancy

Metal excess defect - Fe_0.93O