The Solid State Quiz-1

The Solid State Quiz-1

Dear Readers,

IIT JEE exam which consists of JEE Main and JEE Advanced is one of the most important entrance exams for engineering aspirants. The exam is held for candidates who are aspiring to pursue a career in the field of engineering and technical studies.Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything..

Q1.The edge length of a face-centered cubic unit cell is 508 pin. If the radius of the cation is 110 pm, the radius of the anion is:

•  144 pm
•  288 pm
•  618 pm
•  398 pm

Solution
(a) For face-centered cubic unit cell (e.g., that of ), edge length = Distance between cation and anion pm (given). Putting 110 pm, we get pm

Q2.A TV in fcc is formed by atoms at:

•  3 corners + 1 face center
•  T3 face centers + 1 corner
•  2 face centers + 2 corners
•  T2 face centers + 1 corner + 1 body center

Solution
(b) A TV in fcc is formed by 3 face center atoms and one corner atom. In total, 8 such tetrahedrons are possible

Q3.  The -form of iron has fcc-structure (edge length 386 pm) and -form has bcc structure (edge length 290 pm). The ratio of density in -form and -form is:

•   0.9788
•  1.02
•  1.57
•  0.6344

Solution
(a) forand for/unit cell

Q4. What is the maximum number of layers of atoms in close packed planes that will lie within two imaginary parallel planes having a distance between them of (where is the radius of atom) in the copper crystal (fcc)? (Consider the atoms to be within the parallel planes if their centers are on or with in the two parallel planes)

•  5
•  6
•  7
•  8

Solution
(c) Distance between two layer (A and B) Let is the number of imaginary planes Hence, Thus, maximum number of layers = 7 (see figures below)

 

Q5.The packing fraction for a body-centered cube is

•  0.42
•  0.53
•  0.68
•  0.82

Solution
 (c) Factual statement

Q6. The coordination number of Al in the crystalline state of is

•  2
•  4
•  4
•  8

Solution
(c) Coordination number of Al in in (solid) crystalline state is 6.

Q7.When molten zinc is cooled to solid state, it assumes hcpstructure. Then the number of nearest neighbours of zinc atom will be:

•  4
•  6
•  8
•  12

Solution
(d) hcp has 12 nearest neighbours

Q8.A molecule occupies triclinic lattice with and . If the density of is , the number of molecules present in one unit cell is:

•  2
•  3
•  4
•  5

Solution
(b) Volume of unit cell Mass of unit cell g Number of molecules in one unit cell

Q9.What type of crystal defect is indicated in the diagram given below:

•  Both Frenkel and Schottky defects
•  Schottky defect
•  Interstitial defect
•  Frenkel defect

Solution
(b) Since equal number of cations and anions are missing in the figure given, so it Schottky defect

Q10. The number of hexagonal faces that are present in a truncated octahedron is :

 

•  2
•  4
•  6
•  8

Solution
(d) The truncated octahedron is the 14-faced Archimedean solid, with 14 total faces : 6 squares and 8 regular hexagons. The truncated octahedron is formed by removing the six right square pyramids one from each point of a regular octahedron as :