Match the column I with column II and mark the appropriate choice. Column I (Structure) Column II (Packing efficiency) (A) Simple cubic structure (i) 68% (B) Face centered cubic structure (ii) 74% (C) Body centered cubic structure (iii) 52%

(A) $$\rightarrow $$ (iii), (B) $$\rightarrow $$ (ii), (C) $$\rightarrow $$ (i)

(A) $$\rightarrow $$(i), (B) $$\rightarrow $$ (ii), (C) $$\rightarrow $$ (iii)

(A) $$\rightarrow $$ (ii), (B) $$\rightarrow $$ (i), (C) $$\rightarrow $$ (iii)

(A) $$\rightarrow $$ (iii), (B) $$\rightarrow $$ (i), (C) $$\rightarrow $$ (ii)

MCQ Questions for Class 12 Engineering Chemistry The Solid State Quiz 1

If A is the molecular mass of an element, a is the edge length and

$N$ is the Avogadro's number, then the density for simple cubic lattice is :

0%
$\displaystyle\frac{2A}{Na^3}$
0%
$\displaystyle\frac{4A}{Na^3}$
0%
$\displaystyle\frac{A}{Na^3}$
0%
$\displaystyle\frac{A}{Na^2}$

Explanation

$\text{Density}$

$=$

$\dfrac{\text{Number of molecules present in lattice (Z)} \times \text{Mass of each molecule (m)}}{\text{Volume of lattice (V)}}$

In simple lattice, each lattice has one molecule and mass of each molecule is

$\dfrac{\text{Molar mass (A)}}{\text{Avogadro's number (N)}}$

For simple cubic lattice,

$Z = 1$

Hence,

$\text{density} = \dfrac{Z\times A}{N\times a^{3}}=\dfrac{A}{N\times a^3}$ , where

$a$ is the edge length.

Statement: The molecular orbitals in a crystalline solid are delocalised.

State whether the given statement is true or false.

0%
True
0%
False

Statement: Imperfection in solids give rise to new properties in it.

State whether the given statement is true or false

0%
True
0%
False

Statement: A cubic crystal possess all

$23$ elements of symmetry.

State whether the given statement is true or false

0%
True
0%
False

Explanation

A cubic crystal possesses a total of $23$ elements of symmetry.

Plane of symmetry $= (3 + 6) = 9$

Axes of symmetry $=(3 + 4 + 6) = 13$

Centre of symmetry $= 1$

Identify the amorphous substance from the following.

0%
sugar
0%
clay
0%
salt
0%
iron

An element A (atomic weight

$= 100$ amu) having bcc structure has unit cell edge length of

$400$ pm. Calculate the density of A.

0%
$2.59$ g cm $^{-3}$
0%
$5.188$ g cm $^{-3}$
0%
$10.37$ g cm $^{-3}$
0%
None of the above

Explanation

$density = \dfrac{zM}{N_o \times (a \times 10^{-10})^3}$

for bcc structure z= 2

$d = \dfrac{2 \times 100}{6 \times 10^{23} \times (400 \times 10^{-10})^3}$

$d= 5.188 \text{ g cm}^{-3}$

Hence, the correct option is

$\text{B}$

Which of the following is a non-crystalline solid?

0%
$CsCl$
0%
$NaCl$
0%
$CaF_{2}$
0%
Glass

Explanation

$CsCl$ ,

$NaCl$ and

$CaF_2$ are crystalline solids whereas glass is an amorphous solid as it does not has well developed perfectly ordered crystalline structure. Other amorphous solids include tar, rubber, plastic, butter etc.

The lattice parameters,

$a\neq b\neq c$ and

$\alpha=\gamma=90^{\circ},\,\beta\neq 90^{\circ}$ represents a :

0%
tetragonal system
0%
orthorhombic system
0%
monoclinic system
0%
triclinic system

Explanation

The axial distances and the axial angles,

$a\neq b\neq c$ and

$\alpha=\gamma=90^{\circ},\,\beta\neq 90^{\circ}$ represents a monoclinic system.

None of the edge lengths is equal to each other.

Two of the angles are equal to each other and equal to

$90^0$ . One of the angles is not equal to

$90^0$ .

Example of triclinic crystal systems is

$Na_2SO_4.10H_2O$ .

Hence, the correct option is

$\text{C}$

Bravais lattices are of___________.

0%
$10$ types
0%
$8$ types
0%
$7$ types
0%
$14$ types

Diamond belongs to which of the following crystal system?

0%
Cubic
0%
Triclinic
0%
Tetragonal
0%
Hexagonal

Explanation

Diamond belongs to the cubic crystal system.
The correct axial distances and axial angles are

$a=b=c$ and

$\alpha=\beta=\gamma= 90^{\circ}$ .
All the three edge lengths are equal and all the three angles are equal to each other and equal to

$90^{\circ}$ .

The space occupied in bcc arrangement is_____________.

0%
$74\%$
0%
$70\%$
0%
$68\%$
0%
$60\%$

Explanation

The space occupied in sc, bcc and fcc structures are $52\%$ , $68\%$ and $74\%$ respectively.

Which metal among the followings has the highest packing efficiency?

0%
Iron
0%
Tungsten
0%
Aluminium
0%
Polonium

Explanation

The packing efficiency is the fraction of volume in a crystal structure that is occupied by constituent particles (volume of space occupied by the spheres/total volume). The majority of metals take on either the hcp or bcc structure. Among the given metals

$Al$

occupies hexagonal close-packed (hcp) is having 0.74 packing efficiency and other metals form body-centered cubic (bcc) which has 0.68 packing efficiency.
Thus, Aluminium has the highest packing efficiency in comparison to Iron, Tungsten and Polonium.
Hence (C) is correct answer.

The unit cell in a body centred cubic lattice is given in the figure. Each sphere has a radius,

$r$ and the cube has a side,

$a$ .
What fraction of the total cube volume of empty?

0%
$1 - \dfrac {8}{3} \pi \dfrac {r^{3}}{a^{3}}$
0%
$\dfrac {4}{3}\cdot \pi \dfrac {r^{3}}{a^{3}}$
0%
$\dfrac {r}{a}$
0%
$2 - \dfrac {4}{3} \pi \dfrac {r^{3}}{a^{3}}$

Explanation

$Z_{eff}$ of BCC=

$2$

Volume occupied by atoms=

$2\times \cfrac {4}{3}\pi r^3$

Volume of unit cell=

$a^3$

Packing fraction=

$\cfrac {8}{3}\pi \cfrac {r^3}{a^3}$

Fraction of empty unit cell=

$1-\cfrac {8}{3}\pi \cfrac{r^3}{a^3}$

Answer: (A)

$1-\cfrac {8}{3}\pi \cfrac{r^3}{a^3}$

The closest-packing sequence

$ABC\ ABC .....$ represents:

0%
primitive cubic packing
0%
body-centered cubic packing
0%
face-centered cubic packing
0%
hexagonal packing

Explanation

The closest-packing sequence

$ABAB.....$ represents hexagonal packing.
The closest-packing sequence

$AAAA.....$ represents primitive cubic packing.
The closest-packing sequence

$ABCABC.....$ (with spheres of the third layer placed into octahedral voids) represents face-centered cubic packing.

Hence, option

$C$ is correct.

If the temperature of 500 mL of air increases from 27°C to 42°C under constant pressure, then the increases in volume shall be

0%
15 mL
0%
20 mL
0%
25 mL
0%
30 mL

Mark the incorrect pair from the following.

0%
Schottky defect- Equal number of cation and anions are missing.
0%
Frenkel defect- Dislocation of cation from its normal site to interstitial site.
0%
Impurity defect- $CdCl_2$ in $AgCl$ crystal to create cationic vacancy.
0%
Metal excess defect- $Fe_{0.93}O$

Explanation

${ Fe }_{ 0.93 }O$ , some of

${ Fe }^{ 2+ }$ ions are absent from

$FeO$ and some of

${ Fe }^{ 3+ }$ are present.

So, it is due to metal deficiency defect.

Hence, option "D" is the correct answer.

Match the column I with column II and mark the appropriate choice.

	Column I (Structure)		Column II (Packing efficiency)
(A)	Simple cubic structure	(i)	68%
(B)	Face centered cubic structure	(ii)	74%
(C)	Body centered cubic structure	(iii)	52%

0%
(A) $\rightarrow$ (iii), (B) $\rightarrow$ (ii), (C) $\rightarrow$ (i)
0%
(A) $\rightarrow$ (i), (B) $\rightarrow$ (ii), (C) $\rightarrow$ (iii)
0%
(A) $\rightarrow$ (ii), (B) $\rightarrow$ (i), (C) $\rightarrow$ (iii)
0%
(A) $\rightarrow$ (iii), (B) $\rightarrow$ (i), (C) $\rightarrow$ (ii)

Explanation

For simple cubic structure, packing efficiency is 52% (iii)

For

$fcc$ , packing efficiency = 74%(ii)

For

$bcc$ , packing efficiency = 68%.(i)

So, correct answer is option A.

Potassium has a bcc structure wit nearest neighbour distance

$4.52A^0$ , its atomic weight is

$39$ . Its density (in kg

$m^{-1}$ ) will be:

0%
$454$
0%
$804$
0%
$852$
0%
$908$

Explanation

For b.c.c,

$d = \dfrac{{\sqrt 3 a}}{2}$

$a = \dfrac{{2d}}{{\sqrt 3 }}$

$a=\dfrac{{2 \times 4.52}}{{1.732}}$

$a=5.219{A^ \circ } = 522\,pm$

Hence,

$\rho = \dfrac{{z \times M}}{{{a^3} \times {N_A} \times {{10}^{ - 30}}}}$

Implies that

$\rho=\dfrac{{2 \times 39}}{{{{(522)}^3} \times 6.023 \times {{10}^{23}} \times {{10}^{ - 30}}}}$

$\rho=0.91g/c{m^3}$

$\rho=910kg{m^{ - 3}}$

A solid

$X^+Y^-$ has a bcc structure. If the distance of closest approach between the two atoms is

$173$ pm, the edge length of the cell is:

0%
$200$ pm
0%
$\sqrt{3}/\sqrt{2}$ pm
0%
$142.2$ pm
0%
$\sqrt{2}$ pm

Explanation

For BCC lattice

$r=0.433a$

Lattice is half of the body diagonal , that is

$\dfrac{\sqrt{3}a}{2}=173\ pm$

Thus

$a=\dfrac{173\times2}{\sqrt{3}}$

$=\dfrac{173\times2}{1.73}$

$=200\ pm$

Sodium crystallizes in the cubic lattice and the edge of the unit cell is

$430 pm$ . Calculate no of atoms in the unit cell.
[atomic mass of sodium =

$23.0$ amu.
density of sodium =

$0.9623$ g

$cm^{-3}$ .]

0%
4
0%
3
0%
2
0%
5

Explanation

$\rho=0.9623$

$gcm^{-3}$

$M_{Na}=23$

$amu$

$a=4.3 \mathring A$

$Z=?$

$\rho=\cfrac{Z\times M_A}{N_A\times a^3}$

$\implies 0.9623=\cfrac{Z\times 23}{6.023\times 10^{23}\times 79.5\times 10^{-24}}$

$\implies Z=2$

The atomic radius of metal crystallizing in fcc structure true is

$1.25A^o$ . Hence the volume occupied by atoms in cell crystal is:

0%
$4.078\times 10^{-22}cm^3$
0%
$6.09\times 10^{-23}cm^3$
0%
$3.27\times 10^{-23}cm^3$
0%
$2.68\times 10^{-22}cm^3$

Explanation

For

$FCC$ unit cell

$4r = \sqrt2\times a$ or

$a = 2\sqrt2\times r = 3.5A^o$

Volume

$= a^3 = (3.5\times 10^{-10})^3 = 4.078\times 10^{-22}cm^3$

Number of space lattices present in triclinic system is:

0%
four
0%
three
0%
two
0%
one

Explanation

A triclinic system is a crystal described by a vector of unequal length, as in orthorhombic system. Also, the angles between these vectors must all be different and may include

$90^{\circ}$ . It has the minimum symmetry of all lattices.

It has four space lattices:

In it,

$a\ne b\ne c$ and

$\alpha \ne \beta\ne \gamma=90^{\circ}$

It is seen in

$K_2Cr_2O_7,CuSO_4.5H_2O$ and

$H_3BO_3$

Which parameters are correct for unit cell of

$Na_{2}SO_{4}, 10H_{2}O$ crystal?

0%
$a\neq b\neq c$ and $\alpha =\gamma =90^{o}, \beta \neq 120^{o}$
0%
$a= b= c$ and $\alpha =\beta =\gamma = 90^{o}$
0%
$a= b\neq c$ and $\alpha =\beta =\gamma = 90^{o}$
0%
$a\neq b\neq c$ and $\alpha \neq \beta \neq \gamma =90^{o}$

Explanation

$Na,SO_4,H_2O$ belongs to monoclinic sulphade as for molecule.

Axial length:

$a\neq b\neq c$

Axial angle:

$\alpha=\gamma=90^o,\, \beta\neq 120^o$

1102928_1073234_ans_6dd06fc8917748599e204cd8f07e3ce5.PNG

How many unit cells are present in a cube-shaped ideal crystal of

$NaCI$ of mass

$1.00\ g$ ?

0%
$5.14\times { 10 }^{ 21 }$ unit cell
0%
$1.28\times { 10 }^{ 21 }$ unit cell
0%
$1.71\times { 10 }^{ 21 }$ unit cell
0%
$2.57\times { 10 }^{ 21 }$ unit cell

Explanation

Overall

$4$ units

$NaCl$ are present in one cell

$n$ of moles =

$\dfrac{1}{(23 + 35.5)}$

$= \dfrac{1}{58.5}$

$n$ of molecular =

$6.022 \times 10^{23} \times \dfrac{1}{58.5}$

$\therefore n$ of unit cells =

$\dfrac{molecules}{4}$

$= \dfrac{6.022 \times 10^{23}}{4 \times 58.5}$

$= \dfrac{602.2 \times 10^{21}}{234}$

$= 2.57 \times 10^{21}$

The crystal structure of pure silicon is like:

0%
Diamond
0%
Graphite
0%
Silver
0%
Zinc

Explanation

Silicon crystallizes in the same pattern as

$diamond$ , in a structure which Ashcroft and Mermin call "two interpenetrating face-centered cubic" primitive lattices.

Which one of the following schemes of ordering close-packed sheets of equal-sized spheres do not generate close-packed lattice?

0%
$ABACABAC.....$
0%
$ABCBCABC....$
0%
$ABCABC....$
0%
$ABBAA....$

The correct order of matching of the following compounds is:

List- $I$	List - $II$
Borazole	$CaSO_{4}.1/2 H_{2}O$
Plaster of paris	$C_{60}$
Boric acid	$SiO_{2}$
Quartz	$B_{3}N_{3}H{6}$
Buckminstersullerene	$H_{3}BO_{3}$

0%
$A-3, B-1, C-2, D-5, E-4$
0%
$A-1, B-5, C-3, D-4, E-2$
0%
$A-5, B-2, C-1, D-3, E-4$
0%
$A-4, B-1, C-5, D-3, E-2$
0%
$A-4, B-1, C-5, D-2, E-3$

The empty space left between the spheres in closed packed structure is called voids. The decreasing order of the size of voids is

0%
cubic > octahedral > tetrahedral > trigonal
0%
octahedral > tetrahedral > trigonal > cubic
0%
tetrahedral > trigonal > cubic > octahedral
0%
trigonal > cubic > octahedral > tetrahedral

Explanation

cubic > octahedral > tetrahedral > trigonal

As the ratio of

$\dfrac{r}{R}$ is as follow :

0.732 > 0.414 > 0.225 > 0.155

Which one is an example of amorphous solid?

0%
Glass
0%
Salt
0%
Cesium chloride
0%
Calcium fluoride

Space lattice of

$CaF_{2}$ is:

0%
Face centred cubic
0%
Body centred cubic
0%
Simple cubic
0%
Hexagonal closed packing

Explanation

Space lattice of

$CaF_{2}$ is face centred cubic.

Hence A is correct option

Structure similar to zinc blende is found in:

0%
$AgCl$
0%
$NaCl$
0%
$CuCl$
0%
$TlCl$

Explanation

Zinc blende

$(ZnS)$ has fcc structure and is an ionic crystal having

$4 : 4$ co-ordination number.

Hence C is correct option

How many space lattices are obtainable from the different crystal systems?

0%
$7$
0%
$14$
0%
$32$
0%
$230$

Explanation

There are

$14$ Bravais lattices (space lattices).

Hence B is correct option

The close packing represents

$ABC\ ABC ....$ order of:

0%
Body centred cubic packing
0%
Face centred cubic packing
0%
Simple cubic packing
0%
Hexagonal cubic closed packing

Explanation

The system

$ABC\ ABC$ is also referred to as face-centred cubic or fcc.

What type of lattice is found in potassium chloride crystal?

0%
Face centred cubic
0%
Body centred cubic
0%
Simple cubic
0%
Simple tetragonal

Explanation

Face-centred cubic lattice found in

$KCl$ and

$NaCl$ .

Hence A is correct option

The number of atoms present in a hexagonal close-packed unit cell is :

0%
$4$
0%
$6$
0%
$8$
0%
$12$

The unit cell present in ABCABC, closest packing of atoms is :

0%
hexagonal
0%
tetragonal
0%
face centered cube
0%
primitive cube

Ferrous oxide has a cubic structure and edge length of the unit cell is

$5.0 \,\mathring {A}.$ Assuming the density of ferrous oxide to be

$3.84 \,g/cm^3,$ the no. of

$Fe^{2+}$ and

$O^{2-}$ ions present in each unit cell be :

$(use : N_{A} = 6 \times 10^{23})$ :

0%
$4Fe^{2+}$ and $4O^{2-}$
0%
$2Fe^{2+}$ and $2O^{2-}$
0%
$1Fe^{2+}$ and $1O^{2-}$
0%
$3Fe^{2+}$ and $4O^{2-}$

Explanation

Mass of unit cell

$= d \times V$

$= (5 \times 10^{-8})^{3} \times 3.84 \times 6 \times 10^{23}$

$= 288$ a.m.u.
Mass of formula unit of

$FeO = 56 + 16 = 72$ a.m.u.

$\therefore$ no. of formula unit

$= \dfrac{288}{72} = 4$

The unit cell present in ABAB, closest packing of atoms is :

0%
hexagonal
0%
tetragonal
0%
face centered cube
0%
primitive cube

Statement 1: In a crystal of

$Ca$ , the separation of

$(1,1,1)$ planes is twice as great as that of

$(2,2,2)$ planes.
Statement 2: The length of the side of crystal lattice is

$0.556$ nm

$(\sqrt{12}=3.46)$ .

0%
Statement 1 is True, Statement 2 is True, Statement 2 is a correct explanation of Statement 1.
0%
Statement 1 is True, Statement 2 is True, Statement 2 is not a correct explanation of Statement 1.
0%
Statement 1 is True, Statement 2 is False.
0%
Statement 1 is False, Statement 2 is True.

Explanation

The expression for the distance between two planes is given below:

$d=\dfrac{a}{\sqrt{h^{2}+k^{2}+ \ell ^{2}}}$

$d_{111}\dfrac{0.556}{\sqrt{1^{2}+1^{2}+1^{2}}}=0.321$

$d_{222}=\dfrac{0.556}{\sqrt{2^{2}+2^{2}+2^{2}}}=\dfrac{0.556}{3.46}=0.161$

$d_{111} = 2\times d_{222}$

The statements that are true for clathrates are :

0%
helium and neon can form clathrates
0%
In clathrates, the rare gas molecules are entrapped by cages of water, phenol or quinol
0%
clathrate molecules are formed using weak Van der Walls' forces
0%
stability of clathrated decreases with increase in atomic mass of the rare gas atoms

The space lattice of diamond is:

0%
fcc
0%
bcc with two atoms per unit cell
0%
bcc with 4 atoms per unit cell
0%
simple cubic

Which of the following about the above structure is incorrect?

0%
It has $ccp$ structure.
0%
Each $X$ ion is surrounded by eight $Y$ ions.
0%
The structure is similar to diamond.
0%
$X$ ions are present at the corner of the cube and center of each face.

Explanation

In this type of structure, the coordination number is

$4:4$ i.e. each

$X$ atom is surrounded by 4

$Y$ atoms and each

$Y$ atom is surrounded by 4

$X$ atoms.

So, option B is not correct.

Empty space in ccp lattice is

0%
$26$ %
0%
$45$ %
0%
$90$ %
0%
$30$ %

Explanation

In ccp lattice

$74$ % of the space is occupied by spheres and

$26$ % is empty.

Diamond shows ___________ lusture.

0%
adamantine
0%
resinous
0%
pearly
0%
translucent

Which of the following compounds would be a white, crystalline solid?

0%
$\displaystyle { C }_{ 3 }{ H }_{ 8 }$
0%
$\displaystyle CO$
0%
$\displaystyle Cu{ Cl }_{ 2 }$
0%
$\displaystyle { Cr }_{ 2 }{ O }_{ 3 }$
0%
$\displaystyle MgO$

Explanation

Option

$E$ is the correct answer.

Magnesium Oxide is an ionic compound, formed by the transfer of electrons from one element to the other. Since it is an ionic compound,

$MgO$ is solid. It is also white and crystalline in nature.

Packing efficiency in a unit cell is never 100% because constituent particles are assumed to be:

0%
Spheres
0%
Cuboid
0%
Cubes
0%
Conical

Identify the system of crystal structure, if a = b

$\neq$ c and

$\alpha = \beta = 90^{\circ}$ and

$\gamma = 120^{\circ}$

0%
Monoclinic
0%
Triclinic
0%
Hexagonal
0%
Rhombohedral

Explanation

In the hexagonal system, there is an axes with six-fold rotation symmetry. Just as in the trigonal system, if we chose this axis to be along the c direction, then we have

$a = b ≠ c$ ,

$\ α=β=90^∘$ ,

$γ=120^∘$ . There is only one lattice in the hexagonal system.

Hence, the correct option is

$C$

Solids with regular pattern are called______and irregular pattern are called_______.

0%
crystalline, amorphous
0%
amorphous, crystalline
0%
amorphous, metallic
0%
non-metallic, crystalline

Lattice energy is defined as the energy released when 1 mol of an ionic solid is formed from its ions in the gaseous phase. From the following given compounds, the lattice energy is maximum for (compare the only magnitude)

0%
$N{a_2}O$
0%
NaF
0%
$Mg{F_2}$
0%
$MgC{l_2}$

The radius of a calcium ion is 94 pm and of the oxide, the ion is 146 pm. The possible crystal structure of calcium oxide will be:-

0%
octahedral
0%
tetrahedral
0%
pyramidal
0%
trigonal

CBSE Questions for Class 12 Engineering Chemistry The Solid State Quiz 1 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

CBSE Questions for Class 12 Engineering Chemistry The Solid State Quiz 1 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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