CBSE PREVIOUS YEAR QUESTIONS OF SOLID STATE - CHAPTER 01 - CLASS12 CHEMISTRY

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CBSE follows pattern of questions year after year. So what's better for the practice than the previous year questions of CBSE. 

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CHAPTER- 01 SOLID STATE

2007

1)Find out the number of atoms per unit cell in a face centered cubic structure having only single atoms at its lattice points.

2) Assign reason for the following- 

a) Phosphorous doped silicon is a semiconductor
b) Schottky defect lower the density of a solid

c) Some of the very old glass objects appear slightly milky instead of being transparent.

2008

1) What is the total number of atoms per unit cell in a face centered cubic crystal lattice?

2) What is the coordination number of each ion in a rock salt type structure?

3) What is a semiconductor? Name the two main types of semiconductors and explain their conduction mechanisms?

4) Silver crystallises in fcc lattice. If edge length of the cell is 4.07 × 10–8 cm and density is 10.5 g cm–3, calculate the atomic mass of silver.(NA = 6.02*1023 mol-1)

2009

1) How do metallic and ionic substances differ in conducting electricity?

2) Which point defects of its crystal decrease the density of the solid?

3) Iron has a body centred cubic unit cell with a cell edge of 286.65pm. The density of iron is 7.87g/cm³.Use this information to calculate avagadro’s number.(At. Mass of iron= 56 g/mol)

4) What is the number of atoms in a unit cell of a face centred cubic crystal?

5) Silver crystallizes with fcc unit cells. Each side of the unit cell has a length of 409pm. What is the radius of an silver atom?

2010

1) What type of interactions holds the molecules together in a polar molecular solid?

2) The density of Cu metal is 8.95g/cm³. If the radius of Cu atom be 127.8pm, is the Cu unit cell simple cubic, body centred or face centred cubic?(Given Cu=63.54g/mol, NA=6.02*1023mol-1)

3) Write a distinguishing feature of metallic solids

4) Silver crystallines in fcc lattice. If the edge length in 4.07x 10¯8cm and the density of crystal is 10.5g/cm3.calculate the atomic mass of silver

5) What type of semiconductor is obtained when silicon is doped with arsenic?

6) Silver crystallines in fcc unit cells. Each side of the unit cell has a length of 409pm. What is the raidus of silver atom

2011

1) Explain how you can determine the atomic mass of an unknown metal if you know the mass density and the dimensions of unit cell of its crystal

2) Calculate the packing efficiency of metal crystal for a simple cubic lattice?

2012

1. How may the conductivity of an intrinsic semiconductor be increased

2. Copper crystallizes with fcc unit cells. If the radius of the copper atom is 127.8pm , calculate the density of copper metal. ( Cu= 63.5u, NA = 6.02*1023)

3. Iron has a bcc unit cell with cell dimension of 286.65 pm. Density of iron is 7.87 g cm-3. Use this information to calculate Avogadro’s number. ( Fe= 56.0u)

4. Which stoichimetric defect increases the density of a metal?
5. What are n-type semiconductors?

2013

(a) Why does presence of excess of lithium makes LiCl crystals pink?

(b) A solid with cubic crystal is made of two elements P and Q. Atoms of Q are at the corners of the cube and P at the body-centre. What is the formula of the compound ?

(c ) Aluminium crystalizes in an fcc structure. Atomic radius of the metal is 125pm. What is the length of the side of the unit cell of the metal ?

(d) Account for the following 

(i) Schottky defects lower the density of related solids

(ii) Conductivity of silicon increases on doping it with phosphorous.

2014

1. An element A with density 2.8 g cm3 forms an f.c.c. unit cell with edge length 4 X 10-8 cm. calculate the molar mass of the element.  (Given: NA=6.022 x 1023 mol-1)

2. (i) What type of non-stoichiometric point defect is responsible for the pink colour of LiCl?

    (ii)What type of Stoichiometric defect is shown by NaCl

or

2. How will you distinguish between following pairs of terms-

(i) Tetrahedral and octahedral voids
(ii)Crystal lattice and unit cell

3. (i) Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.

(ii)Which stoichiometric defect does not change the density of the crystal

2015

(i) What is the formula of a compound in which the element Y forms hcp lattice and atoms of X occupy 1/3^rd of octahedral voids?

(ii) Examine the given defective crystal :

 

X⁺     Y^-    X⁺     Y^-   X⁺     Y^-  X⁺    

            X⁺

 Y^-    O     Y^-   X⁺     Y^-  X⁺     Y^- 

 

X⁺     Y^-    X⁺     Y^-   X⁺     Y^-  X⁺    

 

Y^-    X⁺     Y^-   X⁺     Y^-  X⁺     Y^- 

Answer the following questions:-

(a) Is the above defect stoichiometric or non stoichiometric?

(b) Write the term used for this type of defect.

(c) Why do silver halides show this type of defect?

2016

(i) What would be the nature of solid if there is no energy gap between valence band and conduction band?

(ii) An element crystallizes in a bcc lattice with cell edge of 400 pm. Calculate the density if 250g of this element contains 2.5 × 10 ²⁴ atoms?

 

2017

(i) Calculate the number of unit cells in 8.1 g of aluminium if it crystallizes in a fcc structure. ( Al = 27 g mol^-1)

(ii) Based on the nature of intermolecular forces , classify the following solids :

      Silicon carbide , Argon, Benzene, Silver, Sodium sulphate , hydrogen.

(iii) ZnO turns yellow on heating. Why ?

( iv) What is meant by groups 12-16 compounds ? Give an example.

(v) AgCl shows Frenkel defect while NaCl does not. Give reason.

( vi) What type of semiconductor is formed when Ge is doped with Al ?

(vii) What happens when CdCl₂ is doped with AgCl ?

( viii) Why do ferromagnetic substances show better magnetism than antiferromagnetic substances ?

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