Posts Tagged ‘Central Board of Secondary Education’

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 ?

 

Subscribe by Email

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

Categories: AISSCE CHEMISTRY, CBSE Chemistry, Chemistry Model Papers   Tags: , , , , , , ,

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→

 

Be the first to comment - What do you think?  Posted by admin - at 1:27 pm

Categories: AISSCE CHEMISTRY, CBSE Chemistry, Chemistry Sample Papers   Tags: , , , , , , ,

CBSE Chemistry Class 12 Sample Paper – SURFACE CHEMISTRY

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 .

 

Be the first to comment - What do you think?  Posted by admin - at 1:25 pm

Categories: CBSE Chemistry   Tags: , , , , , , ,

CBSE Chemistry Class 12 Sample Paper – ALDEHYDES , KETONES AND CARBOXYLIC ACID

MM : 25                                          TIME : 45 min.
1. Write a chemical equation each to illustrate the following reaction;
(a) Aldol condensation reaction
(b) Cannizzaro reaction
(c) Rosenmund’s reaction
(d) Gattermann – Koch reaction
(e) Clemmensen reduction
2. Convert the following;
(a) Propanone to propene
(b) Propanal to butanone
(c) Benzoic acid to benzaldehyde
(d) Acetone to t-butyl alcohol
(e) Formaldehyde to urotropine
3. Give one chemical test to distinguish Propanal and diethyl ether.
4. Explain why formic acid is more stronger acid than acetic acid ?
5. Explain why carboxylic acid have higher boiling points than alcohols of comparable molecular masses?
6. Why carboxylic acid do not give the characteristic reaction of carbonyl group?
7. Arrange salicylic acid , p-hydroxybenzoic acid , m- hydroxybenzoic acid , benzoic acid in order of increasing acidic strength?
8. Give IUPAC name of Crotonaldehyde .
9. What is Grignard reagent ? How it is used to prepare tertiary butyl alcohol?
10. An alkyl halide when reacts with Aq. NaOH give ‘X’ “X’ in presence of Cu at 573 K gives ‘Y’. ‘Y’ in presence of conc. NaOH gives CH3OH + HCOONa

 

Be the first to comment - What do you think?  Posted by admin - at 1:22 pm

Categories: AISSCE CHEMISTRY, CBSE Chemistry, Chemistry Board Papers, Chemistry Model Papers   Tags: , , , , , , ,

CBSE Class 12 Chemistry Test – Organic Compunds containing Nitrogen

MM : 25                                                                                        TIME : 45min.
1. Write a chemical equation each to illustrate the following reaction:
(a) Carbylamine reaction
(b) Hofmann – bromamide reaction
(c) Gabriel phthalimide synthesis
(d) Balz – Schiemann reaction
(e) Diazotisation reaction
2. Separate primary secondary and tertiary amines on the basis of Hinsberg’s method.
3. Convert the following :
(a) Aniline into fluorobenzene
(b) Toluene into p-toluic acid.
(c) Aniline to sulphanilic acid .
4. Why are amines are less acidic than alcohols of comparable molecular masses?
5. How is basic strength of aromatic amines affected by the presence of electron releasing group on the benzene ring?
6. Explain why Amino group in ethylamine is basic but not in acetamide ?
7. Out of aliphatic and aromatic amines which one is soluble in water and why?
8. Give one chemical test to distinguish between benzyl amine and anilne.
9. What happens when ethylamine is treated with CHCl3 in the presence of ethanolic KOH.
10. Discuss the importance of pH in coupling reaction.

 

Be the first to comment - What do you think?  Posted by admin - at 1:17 pm

Categories: AISSCE CHEMISTRY, CBSE Chemistry   Tags: , , , , , , ,

Next Page »