Prepare for AISSCE (CBSE Class XII) Chemistry through selected Long ANswer Type Questions – Unit 1 – The Solid State
Chapterwise long answer type questions for AISSCE (CBSE Class XII) Chemistry
Unit 1 – The Solid State
- Describe the following
- Hexagonal close packing
- Cubic close packing
- Body centred cubic packing
- What are the seven types of crystal systems? Give their unit cell dimensions. Draw structures of different types of unit cells which are possible for cubic crystal system.
- What do you mean by stoichiometric point defects? Describe briefly the various types of stoichiometric point defects.
- Explain the following.
- Schottky defect
- Frenkel defect
- F – centres
- Explain the conduction behaviour of metals, semiconductors and insulators on the basis of band theory of solids. What is the effect of increase of temperature on electrical conductivity of metals, semiconductors and insulators.
- Explain the following with suitable examples
- Paramagnetic substances
- ferrimagnetic substances
- Ferromagnetic substances
MM : 25 TIME : 40 MIN.
1. Name the catalyst used in the Ostwald process for the manufacture of nitric acid .
2. What happens when a colloidal sol of Fe(OH)3 is mixed with that of As2S3 ?
3. How does alum helps in the purification of water with suspended impurities ?
4. Define gold number .
5. Why sky appears blue in the colour ?
6. Write down the difference between sols and emulsions.
7. What does activity and selectivity of catalyst means ? Explain.
8. What is CMC and Kraft temperature with respect to Micelles formation?
9. What is the difference between adsorption isotherm and adsorption isobar ?
10.In which of the following does adsorption takes place
(i) Silica gel placed in the atmosphere containing water .
(ii) Anhydrous CaCl2 placed in the atmosphere containing water .
11.Differentiate between multimolecular, macromolecular and associated colloids ?
12.Write short note on (a) Electrophoresis (b) Peptization .
13.Differentiate between (a) Physical and chemical adsorption (b) Lyophillic and Lyophobic colloids .