This document contains an unsolved chemistry practice paper from 1985 for the IIT JEE entrance exam. It includes multiple choice, fill-in-the-blank, true/false, and matching questions testing concepts such as the Bohr model, rates of diffusion, Raoult's law, acid-base chemistry, organic chemistry reactions, and properties of elements and compounds. The paper covers 20 sections with over 100 total questions to assess students' mastery of general chemistry topics required for the exam.

1. IIT JEE - Past papersCHEMISTRY- UNSOLVED PAPER – I985

2. SECTION – ISingle Correct Answer TypeThis section contains 20 multiple choice questions. Each question has four choices (A), (B), (C) and (D) out of which ONLY ONE is correct.

3. 01ProblemBohr model can explain:The spectrum of hydrogen atom only Spectrum of an atom or ion containing one electron only The spectrum of hydrogen molecule The solar spectrum

4. Problem 02The molecule having one unpaired electron is:NOCOCN-d.

5. Problem03An example of a reversible reaction is:a.b. c.d.

6. Problem04Rate of diffusion of a gas is:Directly proportional to its density Directly proportional to its molecular weightDirectly proportional to the square root of its molecular weight Inversely proportional to the square root of its molecular weight

7. Problem05For a dilute solution, Raoult’s law states that:The lowering of vapour pressure is equal to the mole fraction of solute The relative lowering of vapour pressure is proportional to the amount of solute in solutionThe relative lowering of vapour pressure is proportional to the amount of solute in solutionThe vapour pressure of the solution is equal to the mole fraction of solvent

8. Solution06The reaction occurs in the galvanic cell:Ag|AgCl|(s) |KCl (soln) |AgNO3 (soln) |AgPtH2 (g) |HCl (soln) | (soln) |AgPtH2 (g) |HCl (soln) |AgCl(s) |AgPtH2 (g) |KCl (soln) |AgCl(s) |Ag

9. Problem07The radius of an atomic nucleus is of the order of: cm10-13cm10-14cm10-8cm

10. Problem08The best indicator for detection of end point in titration of a weak acid and a strong base is:Methyl orange (3 to 4)Methyl red (5 to 6)Bromothymol blue (6 to 7.5)Phenolphthalein (8 to 9.6)Note: Figures in the brackets show the pH range of the indicator

11. Problem09Nitrogen dioxide cannot be obtained by heating:a. b.c. d.

12. Problem10The oxide that gives hydrogen peroxide on treatment with a dilute acid is:a.b. c.d.

13. Problem11The molecular formula of Gluer's salt is :a.b.c.d.

14. Problem12A gas that cannot be collect over water is:a.b.c.d.

15. Problem13The conjugate acid of NH is:a.b.c. NHd.

16. Problem14Acidic hydrogen is present in:EthyneEtheneBenzeneEthane

17. Problem15The compound that will not give iodoform on treatment with alkali and iodine is:AcetoneEthanolDiethyl ketoneIsopropyl alcohol

18. Problem16Anti-Markownikoff addition of HBr is not observed in:PropeneButeneBut –2-enePent-2-ene

19. Problem17The compound that is not a Lewis acid is: a. b. c. d. SnCl

20. Problem18The compound that is most reactive towards electrophonic nitration is:Toluene Benzene Benzoic acid Nitrobenzene

21. Problem19Hydrogen gas will not reduce:Heated cupric oxide Heated ferric oxide Heated stannic oxide Heated aluminum oxide

22. Problem20Electromagnetic radiation with maximum wavelength is:Ultraviolet Radio wave X-ray Infrared

23. SECTION – IIGive the reason in one or two sentences for each of the following.01ProblemAnhydrous HCl is a bad conductor of electricity but aqueous HCl is a good conductor.

24. Problem 02.O-Nitrogen is steam volatile whereas p- nitro phenol is not.

25. Problem03Formic acid is stronger acid than acetic acid.

26. Problem04Graphite is used as a solid lubricant.

27. Problem05Fluorine cannot be prepared from fluorides by chemical oxidation.

28. SECTION – IIIComplete the following sentences

29. 01ProblemThe rate of chemical change is directly proportional to _________.

30. Problem 02The terminal carbon atom in butane is ___________ hybridized..

31. Problem03On Milliken scale, the average of ionization potential and electron affinity is known as _____________.

32. Problem04The number of neutrons in the parent nucleus which gives 14N on beta emission is __________.

33. Problem05Sodium dissolved in liquid ammonia conducts electricity because_________.

34. SECTION – IVTrue or falseThis question contains five statements, each of which is either true of false. Indicate your choice of the answer in the answer-book by writing TRUE or FALSE for each statement.

35. 01ProblemKinetic energy of molecule is zero at C

36. Problem 02Carbon tetrachloride is inflammable.

37. Problem03All molecules with polar bonds have dipole moment.

38. Problem04A gas in a closed container will exerts much higher pressure due to gravity at the bottom than at the top.

39. Problem05M-Chlorobromobenzene is an isomer of m-bromochlorobenzene.

40. Problem06Iodide is a better nucleophile than bromide.

41. Problem07 ­ is nonlinear molecule.

42. Problem08Heat capacity of a diatomic gas is higher than that of a monatomic gas.

43. Problem09Addition of ammonium chloride to a solution containing ferric and magnesium ions is essential for selective precipitation of ferric hydroxide by aqueous ammonia

44. Problem10Solubility of sodium hydroxide increases with increase in temperature.

45. SECTION – VArrange the following in order of their sentences

46. 01ProblemDecreasing ionic size

47. Problem 02Increasing acidic property ZnO, MgO

48. Problem03Increasing first ionization potential Mg, Al, Si, Na

49. Problem04Increasing reactivity towards HCN , HCHO, C2H5COCH3

50. Problem05Increasing bond length

51. SECTION – IVMatch the following

52. 01ProblemSpinelFelsparCerussiteMalachite Kisserite

53. Problem 02Liquid air Deacon Process Parke process Nitric oxide Claude process Silver Ostwald process Chlorine Solvay process

54. Problem03Phenol colored glass antichlor Salicylic acid refractory material Quick lime antisepticCuO analgesic

55. Problem04Aston radium Priestley radioactivityRamsay oxygenMarie Curie inert gas Becquerel mass spectrum

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