Posts Tagged ‘Mathematics’

CBSE Class 12 Chemistry Sample Paper – HALOALKANES AND HALOARENES

MM : 25                                       TIME : 45 MIN.
1. Give IUPAC names of the following compounds:
(a) CH2=CH-CH – C=CH2
C2H5 Cl
(b) CH3-CH2-CH-C6H5Br
CH3
2. Write the structure of the following organic halogen compounds :
(a) 4-tert-butyl-3-iodoheptane
(b) 2-(2-chlorophenyl)-1-iodooctane
3. Explain the following reaction:
(a) Friedel craft alkylation reaction.
(b) Wurtz reaction
(c) Sandmeyer’s reaction
(d) Finkelstein reaction
4. Convert the following:
(a) Ethane to bromoethene
(b) But-1-ene to but-2-ene
(c) Propene to propyne
(d) Benzyl alcohol to 2-phenylethanoic acid
(e) Aniline to chlorobenzene
5. Explain Markownikoff’s rule with example.
6. Explain the following
(a) Vinyl chloride is hydrolysed more slowly than ethyl chloride
(b) The treatment of alkyl chloride with aqueous KOH leads to the formation of alcohols but in the presence of alcoholic KOH , alkenes are the major products.
7. Distinguish between C2H5Br and C6H5Br through chemical test .
8. What are Enantiomers and Racemic mixtures ?
9. Predict the order of reactivity of the following compounds in SN1 reaction C6H5CH2Br , C6H5CH(C6H5)Br , C6H5CH(CH3)Br , C6H5C(CH3)(C6H5)Br
10. What is chemical name of D.D.T ? How it is prepared ?

 

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Be the first to comment - What do you think?  Posted by admin - February 21, 2013 at 1:29 pm

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CBSE Class 12 Chemistry Sample Paper – p- BLOCK ELEMENTS

MM : 30                            TIME : 40 MIN.
1. PCl5 is ionic in nature in solid state .Explain.
2. Out of NH3 and PH3 which one is more basic and why?
3. Explain why nitric oxide shows different behavior in gaseous and liquid state?
4. Explain why both N and Bi do not form pentahalides while phosphorus does ?
5. What is electron gain enthalpy ? Why its value for S is higher than O?
6. SF4 undergo hydrolysis but not SF6 why?
7. Why Fluorine does not exhibit positive oxidation state?
8. What are interhalogen compounds ? Why they are more reactive than halogens ?
9. Addition of Cl2 to KI solution give it a brown colour but excess of Cl2 turns it colourless. Why?
10.Explain why only Xe can form different types of compounds from all noble gases ?
11.Why CO2 exist as a gas but SiO2 act as solid at room temperature ?
12.Explain why SO2 act as oxidising agent as well as reducing agent but SO3 can act as only oxidising agent ?
13.Write balanced equation for the following
(i) NaCl is heated with sulphuric acid in the presence of MnO2 .
(ii) Cl2 gas is passes into a solution of NaI in water .
14.How are XeO3 and XeO4 prepared ?
15.Complete the following equations :
(i) NaOH (aq) + Cl2 ( aq) →
(ii) P4 + NaOH (aq) + H2O→

 

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CBSE Class 12 Chemistry Test – Solid State

MM : 25 TIME : 40 MIN.
1. Give an example of ionic compound which show Frenkel defect.
2. What type of semiconductor is obtained when silicon is doped with Arsenic?
3. How do metallic and ionic substances differ in conducting electricity ?
4. How are the following properties of the crystals affected by Schottky and Frenkel defects
(i) Density (ii) Electrical Conductivity
5. What is the number of atom in a unit cell of
(i) face centered cubic structure
(ii) body centered cubic structure
6. What are F – centers ? Why are solids containing F – centers paramagnetic?
7. Account for the following :
(i) Fe3O4 is a ferromagnetic at room temperature but becomes paramagnetic at 850 K.
(ii) Zinc oxide on heating becomes yellow.
(iii) Frenkel defect does not change the density of AgCl crystal .
8. Chromium metal crystallizes in a body centered cubic lattice . The length of the unit cell edge is found to be 287 pm . Calculate the atomic radius of chromium
9. The density of Cu metal is 8.95 g cm-3. If the radius of Cu atom is 127.8 pm . Is the copper unit cell a simple cubic , a body centered or a face centered cubic structure ?
10. A cubic solid is made of two elements X and Y . Atoms Y are at corner of the cube and X at body centre . What is the formula of the compound ?
11. Calculate the distance between Na+ and Cl- ion in NaCl crystal if its density is 2.165 g cm-3 (Molar mass on NaCl = 58.5 g mol-1 )

 

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CBSE Chemistry Question Bank for Class 12 – The Solid State

CBSE Chemistry Question Bank for Class 12

The solid State

Very Short Answer type Questions

  1. Why are solids rigid?
  2. Name two types in which solids are broadly classified.
  3. Give one example each for a crystalline and amorphous solid.
  4. How many atoms per unit cell are present in (i) hcp (ii) fcc (iii) bcc
  5. How many tetrahedral holes are present per unit cell in an (1)hcp structure and (2) fcc structure?
  6. What type of coordination would you expect when (1)all the tetrahedral holes in an fcc structure of  anions are occupied by cations, (2) half of the tetrahedral holes in an fcc structure of anions are occupied by cations and (3) all the octahedral holes of an fcc structure

 

Be the first to comment - What do you think?  Posted by admin - February 18, 2013 at 4:10 pm

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