Statement 1: | Glass considered a super cooled liquid. |
Statement 2: | Glass has tendency to flow slowly. |
Column I | Column II |
a. Potassium sulphate | i. Molecular (non-polar) solid |
b. Benzene | ii. Ionic solid |
c. Water | iii. Covalent or network solid |
d. Graphite | iv. Hydrogen bonded molecular solid |
Match the items in column I with the items in column II.
Column I | Column II |
a. Hexagonal unit cells | i. a ≠ b ≠ c and α=γ=90°β≠90° |
b. Face-centred unit cells | ii. 2 atoms per unit cells |
c. Monoclinic unit cells | iii. 4 atoms per unit cell |
d. End-centred unit cells |
iv. a = b ≠ c and α = β = 90° γ = 120° |
1. a-iv; b-ii; c-i, d-iii
2. a-ii; b-i; c-iv, d-iii
3. a-iv; b-iii; c-i, d-ii
4. a-iii; b-iv; c-i, d-ii
Statement 1: | ZnS shows Frenkel defect. |
Statement 2: | AgBr shows Frenkel as well as Schottky defect. |
Column I | Column II |
a. Tin | i. Polar molecular solid |
b. Urea | ii. Metallic solid |
c. Zinc sulphide | iii. Covalent or network solid |
d. Silicon carbide | iv. Ionic solid |
Assertion (A): | Due to metal deficiency defect, ZnO gives the appearance of yellow color |
Reason (R): | O2- ion occupies anion vacancy and forms F - center |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | Both (A) and (R) are false. |
Column I: Solids | Column II: Types |
a. Polyurethane | i. Crystalline |
b. Naphthalene | ii. Amorphous |
c. Benzoic acid | |
d. Teflon |
Assertion (A): | Solids are rigid. |
Reason (R): | The constituent particles of solids cannot move from their positions. |
1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
3. | (A) is true but (R) is false. |
4. | (A) is false but (R) is true. |
Assertion (A): | In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from its unit cells. |
Reason (R): | In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality. |
1. | (A) is false but (R) is true. |
2. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
3. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
4. | (A) is true but (R) is false. |
Incorrect statements regarding quartz glass are-
(a) This is a crystalline solid
(b) Refractive index is same in all the directions
(c) This has definite heat of fusion
(d) This is also called supercooled liquid
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, c)