CHEMISTRY MODEL PAPER ,CBSE SET-1

                                   

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SET-1 -2018 MODEL SET PAPER
             CLASS - XII CHEMISTRY MODEL PAPER – (043)—2018 
 Time : Three hour                                                                  Max. Marks : 70
 General Instructions :- 
 1. All questions are compulsory.
 2. Question No. 1-5 are very short answer questions and carry 1 mark each. 
 3. Question No. 6-10 is short answer questions and carries 2 marks each. 
 4. Question No. 11-22 is also short answer questions and carries 3 marks each.
 5. Question No. 23 is value added questions and carry 4 marks.
 6. Question No. 24-26 carry 5 marks 
 7. Use log tables if necessary, use of calculators is not allowed. 


 Q1.Write composition of dettol.? 1

 Q2. What is role of NaCN in froath flotation process.? 1

 Q 3. What is relation between Zr and Hf.? 1 

 Q4. Write IUPAC name of the following compound C6H5CH(OH)-CONH2. 1

 Q5.Why density decrease during schottky defect.? 1 

 Q6. 19.5 gm of CH2FCOOH were dissolve in 500 gm of water Then it dippresed F.P by 10C If Kf is 1.86 K Kg/ mol. Then find out vant Hoff facor and dissociation constant? 2

 Q7. 50% of a substance disintegrate in 10 minute follow the first order kinetics.How much time it will take to complete 75%. 2 
 Q8.Drow the structure of (i)H3PO4 (ii) XeOF4. 2 
 Q9. Urea (molar mass = 60 g mol¯ 1) is present in a solution having osmotic pressure of 4.12atm. Calculate the weight of urea present in it if the room temperature is 2700 c.If same weight of glucose has been taken in place of urea then find out osmotic pressure. 2
 OR
 If 0.2M K4[Fe(CN)6] undergoes 40% dissociation.Find out its vant hoff factor and dissociation constant 
 Q10.Write all the chemical reactions for the preparation of H2SO4.? 

 Q11. Define (ii)What do you mean by Electrophoresis. 3 
 (i)What do you mean by Zwiter ion.? 
 (ii)Give chemical equation when glucose react with red phosphorous and HI..
 (iii)Why humane beings are unabl to digest cellulose.?. 3

 Q13. Define the followings:-

 (i) What is Glycosidic linkage.give example.? 
 (ii) What is PHBV.give their uses.. 
 (iii) What are Tranquilizres drugs.why we should not use them without the supervision of doctor. 3

 Q14. (i)What is Kohlrausch,s Law. 1 (ii)Conductivity of 0.00241M acetic acid is 7.896x10-5 S Cm-1.Calculate its molar conductivity and if standard molar conductivity is 390.5 Scm2 mol-1.What is its dissociation constant.? 2 

Q15. Write short notes on the following name reaction : 
 (i) Clemensen reaction 
 (ii)Rosenmund reaction 
 (iii)Garbriel pthalamide reaction 3 

 Q16. (a)Write chemical tests to distinguish between compounds in each of the following pairs: (i) Propyl alcohol and Ethyl alcohol 
 (ii) Butane-2-ol and Butanaol 

 (b)Why Direct nitration of Aniline is not safe ? 3 
 Q17.Arrange the following compounds in 
 (i)HCHO,CH3CHO.CH3COCH3,CH3COCH2CH3 (Nucleophilic addition reaction 
 (ii) 2-chlorobenzoic acid.2-methy benzoic acid.benzoic acid (Acidic increasing order)
 (iii) CH3CH2CHO,.CH3COCH3,CH3CH3COCH2CH3 (Reaction toward grignard reagent) 3

 Q18.Explain with suitable reason 
 (a)Aniline cant be prepared by Garbriel pthalamide reaction.Expalin. 
 (b) Phenol show acidic character.?
 (c)Why t-Butyl chloride does not give Williamson synthesi with sodium ethoxide.? 3 

 Q19.Give reason 
 (i)What role of semipermeable membrane play in plasmolysis..?
 (ii) K2Cr2O7 have no electron in its d-orbital.yet it is coloured .why 3 
 OR

 (i) A Nacl compound has density of 6.125 g cm-3. If the edge length of its cubic unit cell is 400 pm,. Calculate the molecular mass of Nacl.?
 (ii) Define what is n-type and p- type semiconductor.give example.?.

 Q20. Write names of monomer/s of the following polymers and give important uses..
 (a) Bakelite 
 (b) Nylon-6 
 (c) Decron 3 

Q21. (a) Give the IUPAC name of : K3[Co(cl)3 (NH)3] 
 (b)Drow the splitting diagrame for TETRHEDRAL complex and define what is CFSE.How its magnitude change with strngth with ligands.?. 3

 Q22. Explain the following observations:
 (a) What are antihisatmins.Give an example? 
 (b) What is difference between antiseptics and disinfectant.
 (c)Write three difference between DNA and RNA..? 3

 Q23. A student living on a hill station has surveyed the area and found most cases in hospital are of stones in gall bladder or kidney. He analyzed the water and found presence of Ca2+ ions. He conducted titration of water sample with EDTA (quantitative analysis) to prove his survey. Contextual Question:-
 a) What is the full form of EDTA? (1/2) 
b)What is reason that most of the hill station persons are suffered fron kidney stone (1/2) 
c) Why is EDTA preferred over any other ligand? (1) 
d) What values do you think were in mind of the student while conducting quantitative analysis? (2) 

 Q 24. Explain with reason:-
 (a)Why are aldehydes are more reactive than ketones when undergo nucleophillic addition reaction? 2 
 (b)During preparation of esters from a carboxylic acid and an alcohol in the presence of acid catalyst water or ester formed should be removed as soon as it is formed. 2 
 (c)Why does methanal not give aldol condensation while ethanol gives? 1 
 OR

 (a)An organic compound ‘A’ with molecular formula C8 H8 O2 is reduced to 2- ethyl phenol on treatment with LiAlH 4. ‘A’ forms a oxime with hydroxylamine and gives positive lodoform test and not a Tollen’s test. Identify the compound A and deduce its structure. 

 (b) Write the chemical equations for the following conversions: 
 (i)Ethyl chloride into propanoic acid 
 (ii) Benzyl alcohol into Benzoic acid 
 (iii) Acetone to tert-Butyle alcohol Q25. (a) H2O is liquid but H2S is gas.? 1 

 (b) SF6 is more stale then SF4 2 
 (c) What are allotropic form .Which allotropic form of phosphorous is more reactive .Explain .why? 2 
 OR 
 (a) Give reasons for the following : 
 (i) Oxygen is gas but sulphur is solid.? 1 
 (ii) Why IF7 is more reactive then F2.? 1

 (b) Complete thye following equation
 (i) Cr2 O7-- + H + + C2H5OH ------à 1 
 (ii) XeF 4 + O2 F2 ------à 1 (iii) 2H3 PO3 --------à 1 

 Q 26. Give reasons for the following: 
 (a) ClF3 is known but Fcl3 does not known. ?
 (b) Carbon show more catenation then phosphorous.? 
 (c) ICl is more reactive than I2 ? (d)Drow the structure of N205. (e)Only Xe from inert gases make compound with O and F atom. While other gases does not. 5 

 OR 
 (a) Complete the following reaction:-
 (i)2Mn4 – + 10 I – + 16 H– --------→ (ii)2Mn4 – + H2O + I– --------- →
 (b )Write complete chemical equations for (i)Preperation of KMnO4 from pyrollusite . (3/2) 
 (ii) Preperation of K2Cr2O7 from chromite. (3/2) ***


DR SUDHIR TOMAR (M.Sc(inorganic chemistry),M.SC(physical chemistry)M.Ed,ph.D Watch you tube channel “CHEMISTRY STUDIO BY DR SUDHIR TOMAR)” FOR SOLUTION WATCH YOU TUBE CHANNEL"CHEMISTRY VEDIO"