Chemistry 50 Questions
1. Anisotropic property is shown by
(a) crystalline substances (b) colloidal substances
(c) amorphous substances (d) tiny substances
2. A single substance that exists in two or more forms is called
(a) polymorphous (b) amorphous
(c) isomorphous (d) monomorphous
3. Which among the following is an amorphous solid?
(a) Plastic (b) Benzoic acid (c) Brass (d) Iodine
4. Fullerene is the allotropic modification of
(a) nitrogen (b) carbon (c) sulphur (d) fluorine.
5. Graphite is a good conductor of electricity due to the presence of
(a) lone pair of electrons (b) free valence electrons
(c) cations (d) anions.
6. Among solids the highest melting point is established by
(a) covalent solids (b) ionic solids
(c) pseudo solids (d) molecular solids.
7. The major binding force of diamond is
(a) ionic bond (b) covalent bond
(c) dipole-dipole attraction (d) induced dipole-dipole attraction.
8. In polar molecular solids
(a) the molecules are held together by strong dipole-dipole interactions
(b) the molecules are held together by strong covalent bonds
(c) the molecules are held together by strong ionic bonds
(d) none of these.
9. The binding forces in non-polar solids are
(a) London forces (b) dipole-dipole forces
(c) hydrogen bonds (d) ionic bonds.
10. The force that holds kernels together in the crystal is called
(a) ionic bond (b) hydrogen bond
(c) covalent bond (d) metallic bond.
11. Which type of solid crystals will conduct heat and electricity?
(a) Ionic (b) Covalent (c) Molecular (d) Metallic
12. The number of atoms in a simple primitive cubic unit cell is
(a) 1 (b) 2 (c) 4 (d) 8
13. The number of atoms present in a unit cell of a monoatomic substance (element) of
a simple cubic lattice, body-centred cubic and face-centred cubic are respectively
(a) 8, 9 and 14 (b) 1, 2 and 4
(c) 4, 5 and 6 (d) 2, 3 and 5
14. How many number of atoms are there in a cube based unit cell having one atom on
each corner and two atoms on each body diagonal of cube?
(a) 8 (b) 6 (c) 4 (d) 9
15. Body centred cubic lattice has a coordination number of
(a) 4 (b) 8 (c) 12 (d) 6
16. Relationship between atomic radius and the edge length a of a body-centred cubic
unit cell is
(a) r = a/2 (b) r = √𝑎/2
√3 3𝑎
(c) r = 𝑎 (d) r =
4 2
17. The formula for determination of density of unit cell is
𝑎3 ×𝑁𝐴 𝑍×𝑀
(a) 𝑔𝑐𝑚−3 (b) 𝑎3 ×𝑁𝐴 𝑔𝑐𝑚−3
𝑍×𝑀
𝑎3 ×𝑀 𝑀×𝑁𝐴
(c) 𝑍×𝑁𝐴 𝑔𝑐𝑚−3 (d) 𝑔𝑐𝑚−3
𝑎3 ×𝑍
18. An element (atomic mass = 100 g/mol) having bcc structure has unit cell edge 400
pm. The density of the element is
(a) 10.376 g/cm3 (b) 5.1888 g/cm3
(c) 7.289 g/cm3 (d) 2.144 g/cm3
19. The coordination number of ccp structure is
(a) 8 (b) 12 (c) 6 (d)4
20. In body centred cubic structure, the space occupied is about
(a) 68% (b) 53% (c) 38% (d) 32%
21. The number of tetrahedral voids in the unit cell of a face centred cubic lattice of
similar atoms is
(a) 4 (b) 6 (c) 8 (d) 10
22. In cubic close packing (ccp) arrangement, the pattern of the successive layers will
be designated as
(a) AB, AB, AB ... etc. (b) AB, ABC, AB ... etc.
(c) ABC, ABC, ABC ... etc. (d) none of these.
23. The correct order of the packing efficiency in different types of unit cells is
(a) fcc < bcc < simple cubic (b) fcc > bcc > simple cubic
(c) fcc < bcc > simple cubic (d) bcc < fcc > simple cubic
24. The vacant space in the fcc unit cell is
(a) 23% (b) 26% (c) 32% (d) 74%
25. Which of the following describes the hexagonal close packed arrangement of
spheres?
(a) ABCABA (b) ABCABC (c) ABABA (d) ABBABA
26. Close packing is maximum in the crystal lattice of
(a) simple cubic (b) face centred
(c) body centred (d) none of these.
27. In a solid lattice, the cation has left a lattice site and is located at interstitial
position, the lattice defect is
(a) interstitial defect (b) vacancy defect
(c) frenkel defect (d) schottky defect.
28. Which of the following defects if present, lowers the density of the crystal?
(a) Frenkel defect (b) Schottky defect
(c) Edge dislocation (d) None of these
29. Schottky defect in crystals is observed when
(a) unequal number of cations and anions are missing from the lattice
(b) equal number of cations and anions are missing from the lattice
(c) anion leaves its normal site and occupies an interstitial site
(d) density of the crystal is increased.
30. Frenkel and Schottky defects are
(a) nucleus defects (b) non-crystal defects
(c) crystal defects (d) none of these.
31. As a result of Schottky defect,
(a) there is no effect on the density
(b) density of the crystal increases
(c) density of the crystal decreases
(d) any of the above three can happen.
32. Schottky defect is likely to be found in
(a) AgI (b) NaCl (c) ZnS (d) ZnO
33. Which one of the following is correct?
(a) Schottky defect lowers the density.
(b) Frenkel defect is observed in AgCl solid.
(c) Alloys are formed by substitution defects.
(d) All of these
34. The defects can be minimised by carrying out crystallisation at
(a) fastest rate (b) slowest rate
(c) cannot be minimized (d) both (a) and (b).
35. Which one of the following has Frenkel defect?
(a) NaCl (b) AgBr (c) Graphite (d) Diamond
36. When some of the places of the constituent particles remain unoccupied during
crystallisation, the defect generated is called
(a) interstitial defect (b) vacancy defect
(c) impurity defect (d) none of these.
37. Which of the following types of defects are found in AgCl and AgBr?
(a) Frenkel defect involving cations. (b) Schottky defect.
(c) Interstitial defect. (d) None of these.
38. When NaCl crystal is doped with MgCl2 , the nature of defect produced is
(a) interstitial defect (b) Schottky defect
(c) Frenkel defect (d) impurity defect.
39. Germanium is an example of
(a) an n-type semiconductor (b) a p-type semiconductor
(c) an insulator (d) none of these.
40. Silicon doped with arsenic is an example of type of semiconductor?
(a) p-type (b) n-type (c) n-p-type (d) None of these.
41. Which one of the following statements is wrong?
(a) The conductivity of metals is due to presence of free electrons.
(b) The conductivity of semiconductors increases with increase in temperature.
(c) Ionic solids conduct electricity due to presence of ions.
(d) None of these.
42. Metals are ______ conductors of heat and electricity.
(a) poor (b) good (c) semi (d) any of these.
43. A silicon solar battery makes use of
(a) n-type semiconductor
(b) p-type semiconductor
(c) combination of Si doped with As and Si doped with B
(d) none of these.
44. Silicon is a
(a)Conductor (b) Semiconductor
(c) non-conductor (d) metal complex
45. In a ferromagnetic material
(a) all the magnetic moment vectors are aligned in one direction
(b) half of the magnetic moment vectors point in one direction and rest in the
opposite direction
(c) all the magnetic moment vectors are randomly oriented
(d) net magnetic moment is very small.
46. Which of the following statements is not true?
(a) Paramagnetic substances are weakly attracted by magnetic field.
(b) Ferromagnetic substances cannot be magnetised permanently.
(c) Pairing of electrons cancels their magnetic moment in the diamagnetic
substances.
(d) None of these.
47. A ferromagnetic substance becomes a permanent magnet when it is placed in a
magnetic field because
(a) all the domains get oriented in the direction of magnetic field
(b) all the domains get oriented in the direction opposite to the direction of
magnetic field
(c) domains get oriented randomly
(d) domains are not affected by magnetic field.
48. Which of the following is a diamagnetic substance?
(a) Water (b) Sodium chloride
(c) Benzene (d) All of these
49. The property of a substance due to presence of unpaired electrons is called
(a) paramagnetism (b) diamagnetism
(c) polymerization (d) polymorphosis.
50. Which of the following is paramagnetic substance?
(a) Oxygen (b) Sodium chloride (c) Cobalt (d) Nickel
