The Solid State Class 12 MCQs Questions with Answers
Solid State MCQ Chapter 1 Class 12 Question 1.
Which of the following is not true about the ionic solids?
(A) Bigger ions form the close packed structure.
(B) Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size.
(C) Occupation of all the voids is not necessary.
(D) The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions occupying the voids.
Answer:
(B) Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size.
Explanation:
In ionic solids, smaller ions occupy the voids, and this depends on stoichiometry of the compounds not on the radius of ions.
Solid State Class 12 MCQ Chapter 1 Question 2.
Solid A is very hard electrical insulator in solid as well as in molten slate and melts at an extremely high temperature. What type of solid is it?
(A) Ionic solid
(B) Molecular solid
(C) CovaLent solid
(D) Metallic solid
Answer:
(C) CovaLent solid
Explanation:
Covalent solids are generally hard, act as insulators and melting points of such solids are extremely high.
Class 12 Chemistry Chapter 1 MCQ Question 3.
Which of the following is a network solid?
(A) SO2 (solid)
(B) I2
(C) Diamond
(D) H20 (ice)
Answer:
(C) Diamond
Explanation:
A network solid consists of a network atoms of same or different elements connected , to each other b\ covalent bonds. So, diamond is a network solid as it contains network of carbon * atoms.
Solid State MCQs Class 12 Chapter 1 Question 4.
Graphite cannot be classified as …………
(A) Conducting solid
(B) Network solid
(C) Covalent solid
(D) Ionic solid
Answer:
(D) Ionic solid
Explanation:
Graphite is a conducting solid, network or covalent solid but it cannot be classified as ionic solid.
Solid State Chemistry Class 12 MCQ Question 5.
Which of the following statements is not true about amorphous solids?
(A) On heating they may become crystalline at certain temperature.
(B) They may become crystalline on keeping for long time.
(C) Amorphous solids can be moulded by heating.
(D) They are anisotropic in nature.
Answer:
(D) They are anisotropic in nature.
Explanation:
Amorphous solids are isotropic in nature, i.e., there is no long-range order, and arrangement is irregular along all the directions.
Chapter 1 Chemistry Class 12 MCQ Question 6.
Which of the following is an amorphous solid?
(A) Graphite (G)
(B) Quartz glass (SiO2)
(C) Chrome alum
(D) Silicon carbide (SiC)
Answer:
(B) Quartz glass (SiO2)
Explanation:
Quartz glass (SiO2) is an amorphous solid as it has no long-range order.
Chemistry Class 12 Chapter 1 MCQ Question 7.
The sharp melting point of crystalline solids is due to ……………
(A) a regular arrangement of constituent particles observed over a short distance in the crystal lattice.
(B) a regular arrangement of constituent particles observed over a long distance in the crystal lattice.
(C) same arrangement of constituent particles in different directions.
(D) different arrangements of constituent particles in different directions.
Answer:
(B) a regular arrangement of constituent particles observed over a long distance in the crystal lattice..
Explanation:
The sharp melting point of crystalline solids is due to a regular arrangement of constituent particles observed over a long distance in the crystal lattice.
Solid State MCQ Questions For Class 12 Question 8.
Which of the following conditions favours the existence of a substance in the solid state?
(A) High temperature
(B) Low temperature
(C) High thermal energy
(D) Weak cohesive forces
Answer:
(B) Low temperature
Explanation:
At low temperature substance! exists in solid state. It is due to the decrease in molecular movement which leads to strong cohesive force, that is, the force which tightly i holds the constituent particles together.
MCQ On Solid State Chapter 1 Question 9.
A compound is formed by two elements M and N. The element N forms ccp lattice and atoms of M occupy two atoms an Mercury l/3rd of tetrahedral voids. What is the formula of the compound
(A) MN2
(B) M2N3
(C) M3N2
(D) M2N2
Answer:
(B) M2N3
Explanation:
Suppose the atoms N in the ccp = a
No. of tetrahedral voids = .3a
No. of atoms M = \(\frac {2a}{3}\) : a = 2: 3
Hence compound as M2 : N3
Class 12 Solid State MCQ Chapter 1 Question 10.
Silver crystallises in f.c.c. lattice. It edge length of the unit cells is 4.07 x 10-8 cm density and is 10.5g cm-3. Calculate the atomic mass of silver.
(A) 144 g/mol
(B) 125 g/mol
(C) 125 g/mol
(D) 213 g/mol
Answer:
(C) 125 g/mol
Explanation:
d = \(\frac{Z \times M}{a^{3} \times N_{A}}\)
M = \(\frac{d \times N_{A} \times a^{3}}{Z}\)
M = \(\frac{10.5 \times 6.022 \times 10^{23} \times\left(4.07 \times 10^{-9}\right)^{3} \mathrm{gcm}^{-3}}{4}\)
M = 106.6 g mol-1
Class 12 Chemistry MCQ Chapter 1 Question 11.
The correct order of the packing efficiency in different types of unit cells is ………….
(A) fee < bcc < simple cubic (B) fee > bcc > simple cubic
(C) fee < bcc > simple cubic
(D) bcc < fee = simple cubic Answer: (B) fee > bcc > simple cubic
Explanation:
The correct order of the packing efficiency in different types of unit cells is given below:
fcc > bee > simple cubic
Solid State MCQs Chapter 1 Question 12.
The total number of tetrahedral voids in the face centred unit cell is ……….
(A) 6
(B) 8
(C) 10
(P) 12
Answer:
(B) 8
Explanation:
The total number of tetrahedral voids in the face centred unit cell is 8.
Chemistry Class 12 MCQ Chapter 1 Question 13.
The lattice site in a pure crystal cannot be occupied by ……………
(A) Molecule
(B) Ion
(C) Electron
(D) Atom
Answer:
(C) Electron
Explanation:
Each point in a lattice is known as lattice point which can be either atom, molecule or ion. It is joined together bv a straight line to bring out geometry of lattice in pure crystal constituents. They are arranged in fixed stoichiometric ratio. Hence, existences of free electrons are not possible.
The Solid State Class 12 MCQ Question 14.
Which of the following statements is not true about the hexagonal close packing?
(A) The coordination number is 12.
(B) It has 74% packing efficiency.
(C) Tetrahedral voids of the second layer are covered by the spheres of the third layer.
(D) In this arrangement spheres of the fourth layer are exactly aligned with those of the first layer.
Answer:
(D) In this arrangement spheres of the fourth layer are exactly aligned with those of the first layer.
Explanation:
Hexagonal close packing (hep) can be arranged by two layers A and B one over another which can be diagrammatically represented as: In the above figure the first layer and fourth are not exactly aligned. Thus, statement (D) is not correct while other statements, i.e., (A), (B) and (C) are true.
Class 12 Chemistry Chapter 1 MCQs Question 15.
In which of the following structures coordination number for cations and anions in the packed structure will be same?
(A) Cl–ion form fee lattice and Na+ ions occupy all octahedral voids of the unit cell.
(B) Ca2+ ions form fee lattice and F– ions occupy all the eight tetrahedral voids of the unit cell.
(C) O2- ions form fee lattice and Na+ ions occupy all the eight tetrahedral voids of the unit cell.
(D) S2- ions form fee lattice and Zn2+ ions go into alternate tetrahedral voids of the unit cell.
Answer:
(A) Cl–ion form fee lattice and Na+ ions occupy all octahedral voids of the unit cell.
Explanation:
NaCl unit cell has a fee structure of Cl– ions, and Na+ ions occupy octahedral voids. The radius ratio of 0.524 for NaGl-Suggests an I octahedral void.
Ch 1 Chemistry Class 12 MCQ Question 16.
What is the coordination number in a square close packed structure in two dimensions?
(A) 2
(B) 3
(C) 4
(D) 6
Answer:
(C) 4
Explanation:
In square close packing in two dimensions each sphere is in contact with four of its neighbours. Thus, it Coordination number is 4.
MCQ Of Solid State Class 12 Question 17.
The crystal showing defect is:
Answer:
Option (A) is correct.
Explanation:
The Frenkel defect is formed when an atom or smaller ion (usually cation) leaves its place in the crystal laUice, creating a vacancy, 1 and becomes an interstitial by lodging in a nearby location.
Class 12 Chemistry Ch 1 MCQ Question 18.
Which stoichiometric defect does not change the density of the crystal?
(A) Frenkel defect
(B) Schottky defect
(C) Interstitial defect
(D) F-centres
Answer:
(A) Frenkel defect
Explanation:
In Frenkel defect, one of the ion is missing from its lattice site and occupies an interstitial site. So, density of the crystal does riolfehange.
Solid State MCQ Questions Question 19.
Which of the following defects is also known as dislocation defect?
(A) Frenkel defect
(B) Schottky defect
(C) Non-stoichiometric defect
(D) Simple interstitial defect
Answer:
(A) Frenkel defect
Explanation:
Frenkel defect is also known as 1 dislocation defect because in this defect one of; the ion is missing from its lattice site and occupies an interstitial site.
MCQ Solid State Class 12 Chapter 1 Question 20.
Interstitial compounds are formed when small atoms are dropped under the curved lattice of metals. Whether the following is not the characteristics property of interstitial compounds?
(A) They have high melting points in to pure metals
(B) They are very hard
(C) They retain metallic conductivity
(D) They are chemically very reactive
Answer:
(D) They are chemically very reactive
Explanation:
Interstitial compounds are usually non-stoichiometric and are neither typically ionic nor covalent. Hence, interstitial compounds are chemically inert.
MCQ On Solid State Class 12 Chapter 1 Question 21.
Examine the given defective crystal
How is the density of the crystal affected by this defect?
(A) Density increases
(B) Density decreases
(C) No effect on density
(D) Density first increases then decreases
Answer:
(B) Density decreases
Explanation:
The given defective crystal shows that there is missing of one cation and one anion from their lattice positions which is Schottky defect. Due to missing of ions, density of the crystal decreases.
Assertion And Reason Based MCQs (1 Mark each)
Directions: In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.
(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is True
Question 1.
Assertion (A): Most of the solids possess high melting point.
Reason (R): They have strong intermolecular forces of attraction.
Answer:
(A) Both A and R are true and R is the correct explanation of A
Explanation:
Most of the solids possess high melting point d ue to the presence of intermolecular forces of attraction between their particles.
Question 2.
Assertion (A): Amorphous solids possess a long- range order in the arrangement of their particles.
Reason (R): The formation of amorphous solids involves very rapid cooling.
Answer:
(D) A is false and R is True
Explanation:
Amorphous solids do not possess a long-range order in the arrangement of their . particles because their formation involves rapid cooling.
Question 3.
Assertion (A): Crystalline solids are anisotropic in nature.
Reason (R): Some of their physical properties show same electrical and optical properties in different directions in the same crystal.
Answer:
(C) A is true but R is false
Explanation:
Crystalline solids are anisotropic in nature as some of their physical properties show different electrical and optical properties in different directions in the same crystal.
Question 4.
Assertion (A): Graphite is a good conductor of electricity; however, diamond belongs to the category of insulators.
Reason (R): Graphite is soft in nature, on the other hand diamond is very hard and brittle.
Answer:
(B) Both A and R are true but R is NOT the correct explanation of A
Explanation:
Diamond is a bad conductor of ? electricity because all valence electrons of carbon are involved in bonding. In graphite, however I out of 4 valence electrons are involved in i bonding and the fourth electron remains free , between adjacent layers which makes it a good J conductor. Graphite is soft because parallel lavers i are held together by week vander Waals forces. lowever, diamond is hard due to compact three- I dimensional network of bonding.
Question 5.
Assertion (A): Total number of octahedral voids present in unit cell of cubic packing including the one that is present at the body centre is four.
Reason (R): Besides the body centre these is one octahedral void present at the centre of each of the 4 faces of the unit cell and each of which is shared between two adjacent unit cells.
Answer:
(C) A is true but R is false
Explanation:
Total number of octahedral voids present in unit cell of cubic packing including the one i.e., present at the body centre, is four.
Question 6.
Assertion (A): A two dimensional arrangement where each sphere is in contact with four of its neighbour and has a 2-D coordination number 4 is square close packing arrangement.
Reason (R): In such arrangement, if centres of the neighbouring spheres are joined, a square is formed.
Answer:
(A) Both A and R are true and R is the correct explanation of A
Explanation:
In square close packing arrangement in two dimension, each sphere is in contact with 4 spheres and if the centres of neighbouring \ spheres are joined a square is formed.
Question 7.
Assertion (A): The packing efficiency of simple cubic lattice is 52.4%.
Reason (R): The number of atoms per unit cell is 2.
Answer:
(C) A is true but R is false
Explanation:
For simple cubic lattice a = 2r
Number of atoms per unit cell = 1
Question 8.
Assertion (A): The packing efficiency is maximum for the fcc structure.
Reason (R): The coordination number is 12 in fcc structure.
Answer:
(B) Both A and R are true but R is NOT the correct explanation of A
ExpIanation.
Both ccp and hcp are highly efficient lattice; in terms of packing. The packing efficiency of both types of close packed structure is 74% i.e., 74% of th spac hcpand ccp is filled. The hcp and ccp structures are equally efficient; in terms of packing. The packing efficiency of simple cubic lattice is 52A% and the packing efficiency of body- centred cubic lattice (bcc) is 68%.
Question 9.
Assertion (A): Density of the crystal decreases in Frenkel defect.
Reason (R): In this defect, one of the ion is missing from lattice position and occupies interstitial site.
Answer:
(A) Both A and R are true and R is the correct explanation of A
Explanation:
Density of the crystal does not de creases in Frenkel defect as no ion is missing from the crystal.
Question 10.
Assertion (A): Schottky defect arises when a non-ionic solid is heated.
Reason (R): It happens because some of the lattice sites are vacant in the crystal.
Answer:
(D) A is false and R is True
Explanation:
Vacancy defect arises when a non-ionic solid is heated. It happens because some of the lattice sites are vacant in the crystal.
Case-Based MCQ
I. Read the passage given below and answer the following questions:
All real structures are three dimensional structures. They can be obtained by stacking two dimensional layers one above the other while placing the second square close packed layer above the first we follow the same rule that was followed when one row was placed adjacent to the other.
The second layer is placed over the first layer such that the spheres of the upper layer are exactly above there of the first layer. In his arrangement spheres of both the layers are perfectly aligned horizontally as well as vertically. A metallic element crystallise into a lattice having a ABC ABC pattern and packing of spheres leaves out voids in the lattice.
Question 1.
What type of structure is formed by this arrangement?
(A) ccp
(B) hep
(C) ccp/fcc
(D) none of the above
Answer:
(C) ccp/fcc
Question 2.
Name the non-stoichiometric point defect re-sponsible for colour in alkali metal halides.
(A) Frenkel defect
(B) Interstitial defect
(C) Schottky defect
(D) F – centres
Answer:
(D) F – centres
Question 3.
What is the total volume of atoms in a face centred cubic unit cell of a metal? (r is atomic radius).
(A) 16/3 πr3
(B) πr3
(C) 24/3 πr3
(D) 12/3 πr3
Answer:
(A) 16/3 πr3
Explanation:
Number of atoms per unit cell in fcc = 4
∴ Total volume of atoms present in fcc unit cell = 4 x \(\frac {4}{3}\)πr3 = \(\frac {16}{3}\)πr3
Question 4.
Which of the following statements not true for the amorphous and crystalline solids?
(A) Amorphous solids are isotropic and crystalline solids are anisotropic.
(B) Amorphous solids are short range order and crystalline solids are long range order.
(C) Amorphous solids melt at characteristic temperature while crystalline solids melt over a range of temperature.
(D) Amorphous solids have irregular shape and crystalline solids have a geometrical shape.
Answer:
(C) Amorphous solids melt at characteristic temperature while crystalline solids melt over a range of temperature.
Explanation:
Crystalline solids melt at characteristic temperature while amorphous solids melt over a range of temperature.
OR
Which of the following statements is not true for unit cell?
(A) Each cubic unit cell has 8 atoms on its corners the total number of atoms in one unit cell is 1.
(B) A unit cell is characterized by its dimensions alone the three edges a. b. c.
(C) Each body centred cube cell has 2 atoms in one unit cell.
(D) Each face centred cubic cell contains only one constituent partide present at the centre of each face.
Answer:
(D) Each face centred cubic cell contains only one constituent partide present at the centre of each face.
Explanation:
Each fcc irnit cell contains one constituent particle present at the centre of each face, besides the ones that are at its corners.
II.Study the diagram given below and answer the following questions:
In these questions, a statement of Assertion followed by a statement of Reason is given. Choose the correct answer out of the following choices.
(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the corred expLanation of A
(C) Ais truebut Ris false
(D) A is faLse and R is True
Question 1.
Assertion (A): The diagram shows Schottky defect.
Reason (R): Schottky defect occurs in ionic solids.
Answer:
(B) Both A and R are true but R is NOT the corred expLanation of A
Explanation:
The diagram shows Schottky defect as it has equal number of cationic and anionic vacancies.
Question 2.
Assertion (A): LICI Crystal is pink.
Reason (R): Pink colour of LiCE crystal is due to excess Lithium.
Answer:
(A) Both A and R are true and R is the correct explanation of A
Explanation:
LiCE crystal is pink due to excess Lithium. It is caused by metal excess defect caused by a anionic vacancies(F-centres).
Question 3.
Assertion (A): The crystal lattice density increases due to the defect shown in the diagram.
Reason (R): Tetrahedral voids are surrounded by 4 constituent particles.
Answer:
(D) A is faLse and R is True
Explanation:
The aystal lattice density decreases due to the defect shown in the diagram-Schottky defect.
Question 4.
Assertion (A): AgCI shows Frenkel defect while NaC1 does not.
Reason (R): Frenkel defect is shown when anionic vacancies are occupied by unpaired electrons.
Answer:
(B) Both A and R are true but R is NOT the corred expLanation of A