
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

CBSE Class 12 Board Exam 2016 : Chemistry (Series E)

15 pages, 108 questions, 0 questions with responses, 0 total responses,

	cbse12	+Fave Message
	Profile Timeline Uploads Q & A

Home > cbse12 >

Instantly get Model Answers to questions on this ResPaper. Try now!
NEW ResPaper Exclusive!

Formatting page ...

SET-1 Series ONS U . Code No. U . 56/1/E U U U- S - c U U Roll No. Candidates must write the Code on the title page of the answer-book. U - c U 15 - U U U U U- S - c U U U - 26 U M U , - 15 U - U q 10.15 10.15 10.30 U - U U - S U U Please check that this question paper contains 15 printed pages. Code number given on the right hand side of the question paper should be written on the title page of the answer-book by the candidate. Please check that this question paper contains 26 questions. Please write down the Serial Number of the question before attempting it. 15 minute time has been allotted to read this question paper. The question paper will be distributed at 10.15 a.m. From 10.15 a.m. to 10.30 a.m., the students will read the question paper only and will not write any answer on the answer-book during this period. U ( h ) CHEMISTRY (Theory) U 3 U Time allowed : 3 hours 56/1/E 70 Maximum Marks : 70 1 P.T.O. (i) (ii) 1 5 - U U (iii) 6 10 - U U (iv) 11 22 - U U 3 (v) 23 U U (vi) 24 26 - U U (vii) , U U U U 4 1 2 5 General Instructions : (i) All questions are compulsory. (ii) Questions number 1 to 5 are very short answer questions and carry 1 mark each. (iii) Questions number 6 to 10 are short answer questions and carry 2 marks each. (iv) Questions number 11 to 22 are also short answer questions and carry 3 marks each. (v) Questions number 23 is a value based question and carry 4 marks. (vi) Questions number 24 to 26 are long answer questions and carry 5 marks each. (vii) Use log tables, if necessary. Use of calculators is not allowed. 56/1/E 2 1. SN1 U ? (i) (ii) Which of the following reactions is SN1 type ? (i) (ii) 2. U S U U Write the main reason for the stability of colloidal sols. 3. H2SO4 U U U U U KMnO4 U U U On heating Copper turnings with conc. H2SO4, a colourless gas with pungent smell is evolved which decolourises acidified KMnO4 solution. Identify the gas. 56/1/E 3 P.T.O. 4. U U U U U ? What would be the nature of solid if there is no energy gap between valence band and conduction band ? 5. . . . . . Write the IUPAC name of the given compound : 6. U U U U Write two differences between a solution showing positive deviation and a solution showing negative deviation from Raoult s law. 7. U (i) H2S2O8 (ii) XeF6 Write the structures of the following molecules : (i) H2S2O8 (ii) XeF6 56/1/E 4 8. X U 2,4-DNP U - U U U NaOI U U U LiAlH4 U X Y H2SO4 U U U U-2- X U Y C4H8O An organic compound X having molecular formula C4H8O gives orange-red ppt. with 2,4-DNP reagent. It does not reduce tollens reagent but gives yellow ppt. of iodoform on heating with NaOI. Compound X on reduction with LiAlH4 gives compound Y which undergoes dehydration reaction on heating with conc. H2SO4 to form But-2-ene. Identify the compounds X and Y. 9. PtCl4.6NH3 AgNO3 U AgCl 4 (i) U (ii) . . . . . When a coordination compound PtCl4.6NH3 is mixed with AgNO3, 4 moles of AgCl are precipitated per mole of the compound ? Write : 10. (i) Structural formula of the complex (ii) IUPAC name of the complex U - (t ) 3 4 U U U U S U U U 56/1/E 5 P.T.O. Show that the time required for completion of 3 th of reaction of first order is 4 twice that of half-life (t ) of the reaction. OR Derive integrated rate equation for rate constant of a zero order reaction. 11. b.c.c S U U 400 pm 250 g 2.531024 U U An element crystallizes in a b.c.c lattice with cell edge of 400 pm. Calculate the density if 250 g of this element contain 2.531024 atoms ? 12. U (i) U U U U (ii) U U U U (iii) CH25CH2COOH a- U U CH3CH22COOH Give reasons : (i) The a-hydrogen atoms of aldehydes and ketones are acidic in nature. (ii) Oxidation of aldehydes is easier than ketones. (iii) CH25CH2COOH is more acidic than CH3CH22COOH. 13. U c U # C2H5Cl(g) C2H4(g) 1 HCl(g) / U / U 0 0.30 300 0.50 U S U U ( 56/1/E log 250.301, log 350.4771, log 450.6021) 6 For the first order thermal decomposition reaction, the following data were obtained : C2H5Cl(g) C2H4(g) 1 HCl(g) Time / sec Total pressure / atm 0 0.30 300 0.50 Calculate the rate constant. (Given : log 250.301 log 350.4771 log 450.6021) 14. U (i) U U (ii) U (iii) U Define the following terms : (i) Peptization (ii) Zeta potential (iii) Brownian movement 15. h (i) c S Uc U (ii) U (iii) Write the principle behind the following : (i) Vapour phase refining (ii) Chromatography (iii) Froth floatation process 56/1/E 7 P.T.O. CaCl2 (M5111 g mol21) 3 g U , U CaCl2 M U 16. 100 g (Kf 5 1.86 K kg mol21) Calculate the freezing point of a solution when 3 g of CaCl2 (M5111 g mol21) was dissolved in 100 g of water, assuming CaCl2 undergoes complete ionization. (Kf for water 5 1.86 K kg mol21) 17. U (i) U U (ii) U o (iii) ClF3 U FCl3 Give reasons : (i) Red phosphorus is less reactive than white phosphorus. (ii) Sulphur shows greater tendency for catenation than oxygen. (iii) ClF3 is known but FCl3 is not known. 18. (i) C6 H52COOH (ii) C6H5 NO2 NH3 Br2 / KOH c B A C NaNO21HCl Fe/HCl CuCN A B C 273 - 278K Complete the following reactions : (i) C6 H52COOH (ii) C6H5 NO2 56/1/E NH3 Br2 / KOH heat A B C NaNO21HCl Fe/HCl CuCN A B C 273 - 278K 8 19. U U (i) -S (ii) U U (iii) -6 Write the name of monomers and their structures in the following : (i) Buna-S (ii) Terylene (iii) Nylon-6 20. (i) U U # U U (ii) a- S U U U ? (iii) U U U U U (i) Write the name of monosaccharides which are obtained after the hydrolysis of Lactose. (ii) What type of bonding is responsible for the stability of a-helix ? (iii) Write the difference between Nucleotide and Nucleoside. 21. (a) [CoF6]32 U U, U U S S ( . . Co527) (b) (a) For the complex [CoF6]32, write the hybridization type, magnetic character and spin nature of the complex. (At.number : Co527) (b) Why is the complex [Co(en) 3 ] 31 more stable than the complex [CoF6]32 ? 56/1/E [Co(en)3]31 S 9 [CoF6]32 P.T.O. 22. M U U ? (i) U U (ii) U-1- U-2- (iii) U U (i) (ii) U S U 2- U U ? (iii) KOH AlCl3 n- U S U U U ? CH3Cl U U U U U How do you convert : (i) Chlorobenzene to toluene (ii) But-1-ene to But-2-ene (iii) Ethanol to Ethyl iodide OR What happens when : (i) n-butyl chloride is treated with alcoholic KOH. (ii) 2-chloropropane is treated with sodium in the presence of dry ether. (iii) Chlorobenzene is treated with CH3Cl in the presence of anhydrous AlCl3. Write the chemical equations involved in the above reactions. 56/1/E 10 23. S U . U U U U h U U U U . U U U U U U U U U , U U U U U . U S S U U Q U U (i) . m U ( 2) (ii) U U ? U (iii) U U U ? U Due to hectic and busy schedule, Mr.Singh started taking junk food in the lunch break and slowly became habitual of eating food irregularly to excel in his field. One day during meeting he felt severe chest pain and fell down. Mr. Khanna, a close friend of Mr.Singh, took him to doctor immediately. The doctor diagnosed that Mr.Singh was suffering from acidity and prescribed some medicines. Mr.Khanna advised him to eat home made food and change his lifestyle by doing Yoga, meditation and some physical exercise. Mr.Singh followed his friend s advice and after few days he started feeling better. After reading the above passage, answer the following : (i) What are the values (at least two) displayed by Mr.Khanna ? (ii) What are antacids ? Give one example. (iii) Would it be advisable to take antacids for a long period of time ? Give reason. 24. (a) 298 K U DG0 U log Kc U 2Al(s)1 3Cu21(aq) 2Al 31(aq) 1 3Cu(s) (b) E0cell52.02 V A U B E0 U U U U ? [E0 (Fe21/Fe)520.44 V] 5E0(A21/A)522.37 V : E0(B21/B)520.14 V 56/1/E 11 P.T.O. (a) 0.001 mol L21 3.90531025 S cm21 U U (a) U U CH3COOH l0(H1)5349.6 S cm2 mol21 U l0(CH3COO2)540.9 S cm2 mol21 (b) U U U U ? U (a) Calculate DG0 and log Kc for the following reaction at 298 K : 2Al(s)1 3Cu21(aq) 2Al 31(aq) 1 3Cu(s) Given : E0cell 52.02 V (b) Using the E0 values of A and B, predict which is better for coating the surface of iron [E0(Fe21/Fe)520.44 V] to prevent corrosion and why ? Given : E0(A21/A)522.37 V : E0(B21/B)520.14 V OR (a) The conductivity of 0.001 mol L 21 solution of CH 3 COOH is 3.90531025 S cm21. Calculate its molar conductivity and degree of dissociation(a). Given l0 (H1)5349.6 S cm2 mol21 and l0 (CH3COO2)540.9 S cm2 mol21 (b) 25. (a) 56/1/E What type of battery is dry cell ? Write the overall reaction occuring in dry cell. U (i) Mn2O7 (ii) Zr (iii) MnO U U Hf 12 (b) U U S (MnO2) K2MnO4 KMnO4 U K2MnO4 m U U (a) 3d Sc Ti V Cr Mn Fe Co Ni Cu Zn U (i) U E0(M21/M) (ii) 12 (iii) Zn21 M ? S U ? U ? (b) U S (FeCr2O4) U U U (a) Account for the following : (i) Mn2O7 is acidic whereas MnO is basic. (ii) Zr and Hf exhibit similar properties. (iii) Transition metals form a large number of complex compounds. (b) Write the preparation of K2MnO4 from pyrolusite ore(MnO2). Write the type of magnetism shown by KMnO4 and K2MnO4. OR (a) The elements of 3d transition series are given as : Sc Ti V Cr Mn Fe Co Ni Cu Zn Answer the following : (i) Copper has exceptionally positive E0(M21/M) value.Why ? (ii) Which element is a strong reducing agent in 12 oxidation state and why ? (iii) Zn21salts are colourless.Why ? (b) 56/1/E Write the preparation of sodium dichromate from chromite ore (FeCr2O4). 13 P.T.O. 26. (a) (i) (ii) Zn dust (iii) C6 H52OH (b) (a) (b) (a) U U (i) U U- U (ii) U - U U (i) HNO3 U (ii) (CH3CO)2O/H1 U (iii) U U NaOCH3 U U Q U U (i) U (ii) -2- U 2- -2- Write the product(s) in each of the following reactions : (i) (ii) Zn dust (iii) C6 H52OH 56/1/E 14 (b) Write the chemical equations involved in the following reactions : (i) Reimer-Tiemann reaction (ii) Friedal-Crafts alkylation of anisole. OR (a) What happens when : (i) Phenol reacts with conc.HNO3. (ii) Salicylic acid reacts with (CH3CO)2O/H1. (iii) Ethyl chloride reacts with NaOCH3. Write the chemical equations involved in the above reactions. (b) 56/1/E Distinguish between : (i) Ethanol and Phenol (ii) Propan-2-ol and 2-methylpropan-2-ol 15 P.T.O.

Formatting page ...

Tags : cbse, cbse papers, cbse sample papers, cbse books, portal for cbse india, cbse question bank, central board of secondary education, cbse question papers with answers, prelims preliminary exams, pre board exam papers, cbse model test papers, solved board question papers of cbse last year, previous years solved question papers, free online cbse solved question paper, cbse syllabus, india cbse board sample questions papers, last 10 years cbse papers, cbse question papers 2017, cbse guess sample questions papers, cbse important questions, specimen / mock papers 2018.

cbse12 chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: