Important Questions for Class 12 Chemistry Chapter 1 The Solid State

Very Important Questions for Class 12 Chemistry Chapter 1 The Solid State Class 12 Important Questions

These Class 12 Chemistry Chapter 1 The Solid State Class 12 Important Questions are prepared by our Livelearns team for NEET and JEE Mains. These Very Solid State Class 12 Important Questions are based on the chapter on Chemistry The Solid State Preparation of these questions has been taken from various books including NCERT, Previous year’s question papers, and model papers. So these Chemistry Chapter 1 Solid State Class 12 Important JEE Questions cover all the class 12 subject chemistry topics of Class 12 Chemistry Solid State, These MCQs are very helpful in your preparation for the National Eligibility cum Entrance Test-UG (NEET) and JEE mains. We have provided these questions in PDF format which you can Download by clicking the link as provide below. These Very Important Questions for Class 12 Chemistry Chapter 1 Solid State Class 12 Important Questions are absolutely FREE for you from Livelearns Team.

1. In the cubic arrangement the radius ratio is found to be 0.884. The structure of the crystal will be
   Ans. Body centered cubic
2. Radius ratio of NaCl crystal is 0.532. The structure of the crystal is
   Ans. Octahedral
3. Number of particles present per unit cell of HCP crystal is
4. Ans. Six

4. Iodine is an example of type of solid.
   Ans. Molecular
5. The point defect which decreases the density of a solid is called as
   Ans. schottky defect
6. Give an example of hcp and bcc crystal.
   Ans. hcp ZnS, ZnOP bcc = CsCI, CsBr
7. Find the number of atoms per unit cell in a face centered cubic structure having only single atoms at its lattice point.
   Ans. For Fcc unit cell, no of atoms per unit cell = 8(corners)x 1/8+6(faces)x 1/2= 1 +3 =4
8. Name the point defect responsible for colour in alkali metal halides.
   Ans. The defect is called as metal excess defect. Due to this F-centres are created which is responsible for colour in alkali metal halides.
9. Name the element with which Germanium may be doped to produce n-type semi-conductor
   Ans. Arsenic (Gr-15)
10. When Indium is added to Germanium which type of semiconductor is formed ?
    Ans. Indium (Gr-13) when added to Germanium (Gr-14) then p-type of semiconductor is formed.
11. Write the Bragg’s equation
    Ans. nμ = 2d sin ∅
    where n = order of diffraction
    A= wave length of monochromatic light
    d= distance between two parallel planes containing constituent
    ∅= angle of diffraction
12. Write two characteristies of ionic solid
    Ans. These are water soluble, possess high mp and bp, usually hard and brittle.
13. In molecular solid the constituent particles are held together by.
    Ans. vanders Waal’s force of attraction.
14. Carborandium is a______________type of solid while dry ice is a _______________type of solid.
    Ans. Covalent, molecular.
15. Which type of crystalline solids are good conductor of electricity ?
    Ans. Metallic crystals
16. In a simple cubic crystal packing efficiency is
    Ans. 52.4%
17. In which type of cubic crystal arrangement packing efficiency is maximum ?
    Ans. Face centered cubic crystal (74%)
18. Which type of crystal defect decreases density of a crystal ?
    Ans. Schottky defect.
19. If there are “N tetrahedral voids, then number of octahedral voids is
    Ans. N/2
20. Octahedral void is created by lattice points
    Ans. Six
21. Number of atoms in FCC crystal is
    Ans. 1+3 =4 atoms
22. Which type of crystal defect increases the density of a solid 2
    Ans. interstitial defect.
23. do metallic solid and ionic solid differ in conducting property ?
    Ans. Metallic solids conduct electricity due to movement of electrons and conductivity decreases with increase in temperature. ionic solids conduct electricity due to movement of ions only in fused state or in aqueous solution. The conductivity increases with increase in temperature.
24. Which type of crystal defect does not change the density of solid ?
    Ans. Frenkel defect.
25. What type of semiconductor is formed when silicon is doped with arsenic ?
    Ans. n-type semiconductor
26. What is F-centres ?
    Ans. It is a centre where the electron is entrapped in the anion vacances. This type of crystal defect is also
    known as metal excess defect.
27. What type of semiconductor is formed when silicon is doped with Gallium ?
    Ans.p-type semiconductor
28. Write one application of semiconductor.
    Ans. Semiconductors are used in transistors to detect and amplify radio signals. There are also used in photovoltaic cell to convert light energy to electrical energy.
29. Name the type of structure possessed by unit cell of CsCl.
    Ans. Body centered cubic (bcc) structure.
30. How does electrical conductivity vary with temperature for semiconductors
    Ans. The electrical conductivity increases with increase in temperature for semiconductors due to increase in kinetic energy of electrons.
31. What type of crystal defects are shown by ZnS.
    Ans. Frankel defect is shown by ZnS as the cationic SIze is less than the anionic size.
32. What type of crystal defects are shown by AgBr?
    Ans. AgBr shows both Frenkel and Schottky defects.
33. How many Chloride ions are there around Sodium ion in sodium chloride crystal
    Ans. Six
34. How will you distinguish between tetrahedral void and octahedral void 2 Ans. Tetrahedral void is surrounded by four spheres which lie at the vertices of a regular tetrahedron.Octahedral void is surrounded by six spheres, which lie at the vertices of a regular octahedron.

35. What is co-ordination number?
    Ans. Co-ordination number is the number of nearest neighbours with which an atom is in contact. e.g. In a body centred cubic structure the co-ordination number is 8.
36. Write the equation by which you can find atomic mass of a metal from its density and dimensions of unit cell.
    Ans. M =Pa³Na/Z
    where p = density
    a edge length of unit cell
    z number of atoms in unit cell
    NÀ =Avogadro’s number
37. An ionic compound has a unit cell consisting of A ions at the corners of a cube and B ions on the centres of the faces of the cube. What is the empirical formula of the compound?
    Ans. Number of A ions per unit cell=x8 (corners) = 1 Number of B ions per unit cell =X6 (faces) = 3
    So the empirical formula of the compound is AB, .
38. What is n-type semiconductor
    Ans. When a silicon crystal is doped with atoms of Gr 15 elements (P, As, etc) then four valency electrons of each impurity atom form cOvalent bonds with silicon atoms. Since there is a free electron which is used for
    conduction, so it is called as n-type semiconductor.
39. Gold crystalises in a fcc structure, what is the edge length of the unít cell ? Given radius of gold atom is 0.144 nm
    Ans. For Fcc unit cell, r= √2a/4
    a = 4r/√2=2√2r
    = 2×1.414×0.144
    =0.4973nm
40. What type of forces operate in molecular solids?
    Ans. vander Waal’s force, dipole dipole interaction or hydrogen bonds may operate between the molecules
    of molecular solid.
41. Write two characteristic properties of molecular solid.
    Ans. These are generally soft and have low density. These are bad conductor of heat and electricity
42. Write two characteristic properties of ionic solid.
    Ans. These are soluble in water These are hard and brittle
    These are good conductor of electricity in molten state or aqueous solution.
43. What type of solids are electrical conductor and malleable ?
    Ans. Metallic solids
44. What type of solids are very hard and electrical insulator in solid state as well as in mometen state?
    Ans. Covalent solids
45. What do you mean by packing efficiency ? In which type of crystal arrangements packing efficiency is more ?
    Ans. The percentage of total space filled by the particle in a crystal is called as packing efficiency. The packing efficiency is more in a face centred cubic structure (74%).
46. Khat type of stoichiometric defect is shown by ZnS?
    Ans. Frankel defect.
47. What type of stoichiometric defect is shown by AgBr ?
    Ans. Frankel defect as well as Schottky defect.
48. What is meant by point defect in crystals ?
    Ans. The defects in crystals arises due to the irregularity in arrangement of atoms or ions are called as point defects
49. If ‘a’ is the edge length of the unit cell of a fcc crystal, then what is the distance of closest approach between the two atoms in the crystal 2
    Ans. In a fec crystal 4r = √2a
    2r= a/√2 or d= a/√2
    where d= distance of closest approach between two atoms.
50. An a bcc crystal what is the relationship between atomic radius (r) and edge length (a) ?
    Ans. r=a(√3/4)
51. What is the packing efficiency in a bcc arrangement of crystals ?
    Ans. 68%