MCQ 11 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: ln any ionic solid with Schottky defect, the number of positive and negative ions is same.
Reason: Equal number of cationic and anionic vacancies are present.
- ✓
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: A. Assertion and reason both are correct statements, and reason is correct explanation for assertion.
View full question & answer→MCQ 21 Mark
Directions: In the following questions, the Assertions $(A)$ and Reason$(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: No compound has both Schottky and Frenkel defects.
Reason: Both defects change the density of the solid.
- A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
- B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
- C
If the Assertion is correct but Reason is incorrect.
- ✓
If both the Assertion and Reason are incorrect.
AnswerCorrect option: D. If both the Assertion and Reason are incorrect.
View full question & answer→MCQ 31 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: In $\text{NaCl}$ crystal, each $Na^+$ ion is touching six $Cl^-$ ions but these $Cl^-$ ions do not touch each other.
Reason: The radius ratio $\frac{\text{r}_\text{Na}}{\text{r}_\text{Cl-}}$ is greater than $0.414$ required for exact fitting.
- ✓
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: A. Assertion and reason both are correct statements, and reason is correct explanation for assertion.
$\text{NaCl}$ has face centred cubic structure in which each $Na^+$ is surrounded by $6$ ions and vice$-$versa.
In this octahedral arrangement, coordination number of both $Na^+$ and $Cl^-$ is $6$ for which radius ratio lies between $0.414$ and $0.732.$
This radius ratio does not allow $Cl^-$ ions to touch each other.
View full question & answer→MCQ 41 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: The total number of atoms present in simple cubic unit cell in one.
Reason: Simple cubic unit cell has atoms at its corners, each of which is shared between four adjacent unit cells.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Simple cubic unit cells has atoms at its corner, each of which is shared between eight adjacent unit cells.
Number of atoms per unit cell $=8\times\frac{1}{8}=1$
View full question & answer→MCQ 51 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Molecular solids are characterized by low melting point.
Reason: Molecular solids are made up of covalent molecules.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- ✓
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: B. Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
Low melting point is due to weak intermolecular interaction.
View full question & answer→MCQ 61 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: ln close packing of spheres, a tetrahedral void is surrounded by four spheres, whereas an octahedral void is surrounded by six spheres.
Reason: A tetrahedral void has a tetrahedral shape, whereas an octahedral void has an octahedral shape.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Tetrahedral void is called so because it is surrounded by four spheres tetrahedrally, while octahedral void is called so because it is surrounded by six spheres octahedrally.
View full question & answer→MCQ 71 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: ln $\text{CsCI}$ crystal$, Cs^+$ ions adopt bee arrangement.
Reason: For $N$ atoms adopting bcc arrangement, there are $2N$ tetrahedral voids.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerFor $N$ atoms adopting $fcc$ arrangement, there are $2N$ tetrahedral voids.
View full question & answer→MCQ 81 Mark
Directions: In the following questions, the Assertions $(A)$ and Reason$(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Graphite is a good conductor of electricity however diamond belongs to the category of insulators.
Reason: Graphite is soft in nature on the other hand diamond is very hard and brittle.
- A
Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
- ✓
Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
- C
Assertion is true but Reason is false.
- D
Assertion is false but Reason is true.
AnswerCorrect option: B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
The correct explanation for reason is, In graphite, carbon atoms are arranged in different layers and each atom is covalently bonded to three of its neighboring atoms in the same layer. The fourth electron is free to move which makes graphite a good conductor.
View full question & answer→MCQ 91 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Network solids are also called giant molecules.
Reason: Graphite is soft in nature and conducts electricity.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- ✓
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: B. Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
View full question & answer→MCQ 101 Mark
Directions: In the following questions, the Assertions $(A)$ and Reason$(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Diamond is a precious stone.
Reason: Carbon atoms are tetrahedrally arranged in diamonds.
- A
Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
- ✓
Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
- C
Assertion is true but Reason is false.
- D
Assertion is false but Reason is true.
AnswerCorrect option: B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
It is true that in the diamond structure, carbon atoms are arranged tetrahedrally $(sp^3$ hybridized$)$ but it is not the correct explanation of assertion.
View full question & answer→MCQ 111 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Ionic solids are made up of cations and anions.
Reason: Ionic solids conduct electricity in solid state.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Ionic solids do not conduct electricity in solid state, as ions present in them are not free to move. They conduct electricity in molten state.
View full question & answer→MCQ 121 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: bee and hep has same packing efficiency
Reason: bee arrangement has $2$ atoms per unit cell, while fee has $4$ atoms per unit cell.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
Answer$bcc$ and hep have different arrangements of particles$. bcc$ has $68\%$ and $hcp$ has$ 74\%$ packing efficiency.
View full question & answer→MCQ 131 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: The number of tetrahedral voids is double the number of octahedral voids.
Reason: The size of the tetrahedral voids is half of that of the octahedral void.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
The size of tetrahedral voids is smaller but not half of the octahedral voids.
View full question & answer→MCQ 141 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: $\text{NaCl}$ crystal is sometimes yellow in colour.
Reason: $Na^+$ in the crystal absorbs electron from air and hence gives yellow colour.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
$\text{NaCl}$ shows metal excess defect which results into the formation of $F-$center in the crystal. This $F-$center is responsible for yellow colour of the crystal.
View full question & answer→MCQ 151 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Glass is an amorphous solid.
Reason: Glass has an irregular, random arrangement of atoms
- ✓
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: A. Assertion and reason both are correct statements, and reason is correct explanation for assertion.
View full question & answer→MCQ 161 Mark
Directions: In the following questions, the Assertions $(A)$ and Reason$(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : Stability of a crystal is reflected in the magnitude of its melting.
Reason : The stability of a crystal depends upon the strength of the interparticle attractive force.
- ✓
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
- B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
- C
If the Assertion is correct but Reason is incorrect.
- D
If both the Assertion and Reason are incorrect.
AnswerCorrect option: A. If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
View full question & answer→MCQ 171 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Ionic solids are characterized by high melting and boiling points.
Reason: Ionic solids have coulombic forces of attraction between their ions.
- ✓
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: A. Assertion and reason both are correct statements, and reason is correct explanation for assertion.
Ionic solids have high melting and boiling points because cations and anions present in them are bounded by coulombic forces of attraction.
View full question & answer→MCQ 181 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Crystalline solids are anisotropic.
Reason: Crystalline solids are not as closely packed as amorphous solids.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Constituent particles are closely packed in crystalline solids, and anisotropy is due to different arrangements of constituent particles in different directions.
View full question & answer→MCQ 191 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Crystalline solids melt at a sharp and characteristic temperature.
Reason: Amorphous solids do not have definite enthalpy of fusion.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- ✓
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: B. Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
View full question & answer→MCQ 201 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: In $\text{ZnO},$ the excess $Zn_2^+$ ions are present in interstitial sites.
Reason: Metal excess crystals have either missing cation or anion in interstitial site.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
In metal excess defects, the positive ions are in excess. These may arise either due to anionic vacancies or due to presence of extra cation in interstitial sites.
View full question & answer→MCQ 211 Mark
Directions: In the following questions, the Assertions $(A)$ and Reason$(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : On heating ferromagnetic or ferrimagnetic substances, they become paramagnetic.
Reason : The electrons change their spin on heating.
- ✓
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
- B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
- C
If the Assertion is correct but Reason is incorrect.
- D
If both the Assertion and Reason are incorrect.
AnswerCorrect option: A. If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
View full question & answer→MCQ 221 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: The packing efficiency is maximum for $fcc$ structure.
Reason: The coordination number is $8$ in $fcc$ structure.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
$fcc$ is a close packed structure, thus, it has maximum packing efficiency. The coordination number is $12$ in $fcc$ structure.
View full question & answer→MCQ 231 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Anionic vacancies in alkali halides are produced by heating the alkali halide crystals with alkali metal vapour.
Reason: Electrons trapped in anionic vacancies are referred to as $F-$centres.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- ✓
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: B. Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
View full question & answer→MCQ 241 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Amorphous substances are isotropic.
Reason: Properties like refractive index, electrical conductance have different values in different direction for isotropic substances.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Properties like refractive index, electric conductance, etc. are identical in all directions for isotropic substances.
View full question & answer→MCQ 251 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: $FeO$ is non$-$stoichiometric with $Fe\ 0.950.$
Reason: Some $\mathrm{Fe}^{2+}$ ions are replaced by $\mathrm{Fe}^{3+}$ as $3 \mathrm{Fe}^{2+}=2 \mathrm{Fe}^{3+}$ to maintain electrical neutrality.
- ✓
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- C
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement
AnswerCorrect option: A. Assertion and reason both are correct statements, and reason is correct explanation for assertion.
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
View full question & answer→MCQ 261 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
Assertion: Certain compounds have both Schottky and Frenkel defects.
Reason: Both Schottky and Frenkel defects change the density of the solids.
- A
Assertion and reason both are correct statements, and reason is correct explanation for assertion.
- B
Assertion and reason both are correct statements, but reason is not correct explanation for assertion.
- ✓
Assertion is correct statement, but reason is wrong statement.
- D
Assertion is wrong statement, but reason is correct statement.
AnswerCorrect option: C. Assertion is correct statement, but reason is wrong statement.
Certain ionic solids e.g$, \text{AgBr}$ have both Schottky and Frenkel defects. Only Schottky defects change the density of solids.
View full question & answer→