NSEC' 2004-05 Question Paper

Blazing goIITian

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NSEC' 2004-05 Question Paper
Engineering Entrance , JEE Main , JEE Main & Advanced , nsec question paper olympiad chemistry

To cater to the needs of students who have no means of obtaining the olympiad & NTSE question papers, we have resolved to give out the previous question papers of various Olympiads such as NSEC, NSEA and NSEP. (do'nt have NSEB papers). 

NSEC 2004-05 Question Paper

1. The solubility product of Ag2CrO4 is 1.9 x 10-12. The volume of water in mL that can dissolve 4mg of Ag2CrO4 is about

(a) 150 mL       (b) 1000 mL      (c) 250 mL      (d) 500 mL


2. A mixture of aluminium and zinc weighing 1.67 g was completely dissolved in acid and evolved 1.69 L of hydrogen gas (measured at 273 K and 1 atm pressure). The amount of aluminum in the original mixture is approximately 


(a) 1.8 g      (b) 2.0 g        (c) 1.2 g      (d) 2.2 g   [ (b) is the only LOGICAL answer based on the options given ]


3. The compound that would yield 5-oxo-2-methylhexanal on ozonolysis is



4. The structures of AlCl3 and PCl3 can be described as

(a) both planar      (b) both pyramidal    (c) planar and pyramidal respectively      (d) pyramidal and planar respectively


5. The precipitate of AgCl dissolves in

(a) conc. HNO3   (b) excess HCl     (c) dil. H2SO4   (d) aq. Ammonia


6. Bond orders for NO and NO+ are respectively

(a) 2.5 and 3         (b) 2 and 4        (c) 3.5 and 2.5        (d) 3 and 2


7. The atomic number of copper is 29, Its Effective Atomic Number (EAN) in [Cu(NH3)4]2+ is

(a) 40    (b) 29     (c) 35    (d) 36


8. The following sequence of reactions gives

(a) 1-butanol        (b) 2-butanol      (c) 3,4-hexanediol     

(d) 3-methyl-3pentanol


9. The following stereoisomers are

(a) enantiomers      (b) epimers       (c) diastereomers      (d) identical


10. For water, the maximum number of phases that can be in equilibrium is

(a) 1    (b) 2       (c) 3        (d) 4


11. The largest number of molecules is present in 1 g of

(a) CO2    (b) H2O    (c) C2H5OH     (d) N2O5


12. The non-nucleophilic base is

(a) CN     (b) OC (Me)3   (c) OH   (d) MeO


13. A soap solution in water removes greasy substances by

(a) adsorption        (b) peptization     (c) coagulation      (d) emulsification


14. A gas will approach ideal behaviour at

(a) low temperature and low pressure

(b) low temperature and high pressure

(c) high temperature and low pressure

(d) high temperature and high pressure


15. The compound that has the highest dipole moment is

(a) cis-1,2-dichloroethene

(b) trans-1,2-dichloroethene

(c) cis-1-chloro-2-bromoethene

(d) trans -1-chloro-2-bromoethene


16. A firework gives out crimson coloured light, due to the presence of salts of

(a) calcium     (b) sodium    (c) barium     (d) strontium


17. The fuel that is considered least polluting is

(a) petrol      (b) coke      (c) furnace oil      (d) CNG


18. A certain current passed through a CuSO4 solution for 100 seconds deposits 0.3175 g of Copper. The current passed (in A) is

(a) 4.83       (b) 9.65       (c) 0.965       (d) 0.483


19. The most stable carbocation is


(a)    CH3-S-CH2


(b)   CH3-CH-CH2



(c)    F-CH2


(d)   Cl3C


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20. CCl4 (g) + 2H2O (g) CO2(g) + 4HCl (g)

The standard enthalpies of formation at 298 K for CCl4 (g), 2H2O (g), CO2(g) and HCl(g) are -106.7, -241.8, -393.7, and -92.5 kJmol-1 respectively. The value of ΔHo298 for the above reaction is

(a) -137.7 kJ       (b) 173.4 kJ       (c) -173.4 kJ       (d) 137.7 kJ


21. The correct representation of the plot of rate v/s time for the reaction ABC is


22. The hybridisations of atoms 1 to 4 in

              1      2      3      4

(MgBr)CH2-CH2-CO-NH2 are respectively

(a)    sp2, sp3, sp2, sp3

(b)   sp3, sp2, sp2, sp2

(c)    sp3, sp3, sp2, sp2

(d)   sp2, sp2, sp2, sp3


23. The product (B) of the following sequence of reactions is



24. The ratio of the energy of a photon of wavelength 2000 Å to that of one with wavelength 4000 Å is

(a) ¼     (b) 4     (c) ½    (d) 2


25. White lead is

(a) PbCO3     (b) PbCO3.PbO     (c) 2PbCO3.Pb(OH)2       (d) 2PbSO4.PbO


26. A container with a radioactive isotope of half-life 3 days was sent to a laboratory. The activity of the same on 12th day was found to be 3 microcuries (μCi). Hence the initial activity (μCi) of the isotope when packed was

(a) 12      (b) 24         (c) 36        (d) 48


27. The aromatic compound would be



28. The gas which is commonly used for ripening of fruits is

(a) nitric oxide     (b) acetylene      (c) butane     (d) oxygen


29. One of the following classes of compounds is NOT a biopolymer

(a) Proteins     (b) Steroids     (c) Nucleic Acids      (d) Glycogens


30. Insulin, a hormone secreted by the pancreas, is a

(a) carbohydrate     (b) steroid      (c) protein     (d) nucleic acid


31. The reagent which can react with 2-bromopropane to give mainly a substitution product is

(a) sodium sulphate       (b) sodium cyanide      (c) sodium chloride     (d) sodium ethoxide


32. The central dogma of molecular genetics states that genetic information flows from

(a) carbohydrate → proteins → nucleic acids

(b) DNA → RNA → proteins

(c) proteins → RNA → DNA

(d) RNA → DNA → proteins


33. The configurations of the asymmetric centers in (X) and (Y) molecules are respectively



(a) S,S   (b) S,R   (c) R,R    (d) R,S


34. The emission of light by fireflies is an example of

(a) fluorescence    (b) Phosphorescence

(c) Chemiluminescence     (d) Thermoluminescence


35. The heat of hydrogenation of 1-butene and 2-butene are respectively ΔH1 and ΔH2. The correct relationship between ΔH1 and ΔH2 is

(a) |ΔH1| > |ΔH1|

(b) |ΔH1| < |ΔH2|

(c) |ΔH1| = |ΔH2|

(d) ΔH1 + ΔH2 = 0


36. An enzymatic partial hydrolysis of starch and cellulose give disaccharides maltose and cellobiose respectively. Hence, matlose and cellobiose differ with respect to

(a) Molecular Mass      (b) Configuration at the glycoside linkage

(c) Placement of the glycoside linkage   

(d) ring sizes of the constituent sugar residues


37. The group in the periodic table that contains the elements in all different physical states at room temperature is

(a) V A (or 15)      (b) I A (or 1)      (c) VII A (or 17)    (d) IV A (or 14)


38. The boiling point of a glucose solution is higher than that of water because

(a) glucose forms extensive hydrogen bonding with water

(b) glucose does not dissociate in water

(c) its vapour pressure is higher that that of water at a given temperature

(d) its vapour pressure is less than that of water at a given temperature


39. The substance that gives a primary amine on hydrolysis is

(a) nitroparaffin     (b) alkyl cyanide    (c) oxime    (d) alkyl isocyanide


40. The reagent with which both hexanal and 2-pentanone react is

(a) Fehling’s solution      (b) a Grignard reagent      (c) Schiff’s reagent    

(d) Tollen's reagent


41. The temperature of an ideal gas increases in an

(a) adiabatic expansion     (b) isothermal expansion

(c) adiabatic compression     (d) isothermal compression


42. The value of Δn for the combustion reaction of one mole of benzene in gaseous state when both the reactants and products are at 298 K is

(a) 1      (b) 0     (c) ½    (d) – ½


43. For two moles of an ideal gas

(a) Cv – Cp = R

(b) Cp – Cv = 2R

(c) Cp – Cv = R

(d) Cv – Cp = 2R


44. The salt that can be used in the salt bridge of an electrochemical cell is

(a) FeCl­­3    (b) AgCl    (c) CH3COONa     (d) KNO3


45. The weakest base among the following is

(a) C6H5SO3

­(b) C2H5O

(c) C6HO

(d) CH3-CH=CH-CH-O


46. Among the following, a good solvent for a Grignard reagent formation would be

(a) tert. Butanol

(b) dimethyl ether

(c) difluoromethane

(d) tetrahydrofuran


47. In its 0.20 M solution, methanoic acid has degree of dissociation 0.032. Hence its dissociation constant would be

(a) 2.1 x 10-2

(b) 2.1 x 10-4

(c) 1.1 x 10-6

(d) 9.6 x 10-8


48. A pair that forms a buffer system is

(a) BaCl2 + Ba(NO)

(b) NaCl + HCl

(c) Na3PO4 + Na2HPO4

(d) AgCN + KCN


49. Toluene is o/p directing with respect to an electrophilic substitution reaction due to

(a) +I effect of methyl group

(b) +I as well as +M effect of the methyl group

(c) hyperconjugation between the methyl group and the phenyl ring

(d) +M effect of the methyl group


50. The product obtained when propionic acid amide is distilled with phosphorus pentoxide is

(a) (CHCH2CO)2O

(b) CH3CH2CN




51. The radioisotope used in the treatment of hyperthyroidism is

(a) Co-60    (b) Na-24    (c) I-131     (d) I-123


52. Among the following, the pair of enantiomers is

(a) I and III         (b) II and IV       (c) II and III      (d) III and IV


53. Inductive effect is a polarization of a

(a) sigma bond     (b) π-bond      (c) coordinate bond       (d) conjugated system


54. The product obtained when 4-hydroxybenzene sulphonic acid is treated with an excess of bromine water is

(a) 2-bromo-4-hydroxybenzene sulphonic acid

(b) 2,3-dibromo-4-hydroxybenzene sulphonic acid

(c) 2,6-dibromo-4-hydroxybenzene sulphonic acid

(d) 2,4,6-tribromophenol


55. The treatment of glycerol with conc. H2SO4 gives

(a) 2,3-epoxy-1-propanol

(b) 1,3-propanediol

(c) propenal

(d) 1,2-propadiene


56. At equilibrium H5HHHHhhh, the value of the Gibbs free energy change of a reaction is

(a)    greater than zero

(b)   equal to zero

(c)    minimum

(d)   less than zero


57. A buffer solution is prepared by mixing 0.050 moles of a weak acid, HA and 0.20 moles of NaA in sufficient amount of water to give 500 mL of solution (KA for HA = 4.5 x 10 -4). The pH of this solution is

(a) 1.97     (b) 2.17      (c) 2.74      (d) 3.95


58. Consider various species generated when H3PO4 is dissolved in water. Among these, the conjugate acid of HPO42- is

(a) H3PO4     (b) H2PO4-    (c) PO43 -    (d) H3O+


59. A 1.0 molal solution with the lowest freezing point is that of

(a) FeCl3       (b) HCl      (c) KCl       (d) MgCl2


60. If a weak base has the dissociation constant, KB, then the value of the dissociation constant, K­A, of its conjugate acid is given by

(a) 1/KB       (b) Kw/KB       (c) KB/KW     (d) KWKB


61. The number of possible isomers for di-nitronapthalene is

(a) 12       (b) 10        (c) 8        (d) 14


62. CH3COOH  (a)         HCOOH  (b)          CH2ClCOOH   (c)           PhCOOH   (d)

The order of acidity in the above series of compounds is

(a)    d<b<a<c

(b)   a<b<c<d

(c)    a<b<d<c

(d)   a<d<b<c


63. The fig. below schematically represents the energy changes with the progress of a reaction, A + B → C + D. Here α and β are positive. The ΔE for the reaction is


(a) –(α + β)        (b) – γ + α       (c) – α        (d) – β


64. The rate constant for a chemical reaction is related to temperature by the relation log k = 10 -. If the temperature is raised from 227?C to 327?C, the rate of this reaction would increase by a factor of about

(a) 20      (b) 46      (c) 210      (d) 3.4 x 106


65. The genetic code allows more than one codon for one amino acid. One of the codons for the amino acid isoleucine is AUU. The two other codons for isoleucine are

(a) AUC, AAU       (b) AUC, AUA       (c) AUA, ACU      (d) AAU, AUA


66. A compound undergoes the following sequence of reactions and gives the product (C8HO3).

(i) reaction with dilute aq. NaOH


(iii) treatment with acidic Na2Cr2O7

(iv) heating

Hence the compound is



67. 20g of solute X is dissolved in 50 g of water, 15 g of solute Y is dissolved in 70 g of benzene. The molalities of the two solutes in these two solutions are the same. Hence, the ratio of the molecular wrights of solute X to that of solute Y is

(a) 7 : 5       (b) 4 : 3        (c) 15 : 28        (d)  28 : 15


68. RMS velocity of sulphur trioxide is found to be equal to the most probable velocity of another gas at the same temperature. Hence the molecular weight of the gas is

(a) 46      (b) 65       (c) 53         (d) 80


69. Heat of combustion of ethanol at constant pressure and at 298 K is found to be –Q kJmol-1. Hence, heat of combustion of ethanol at the same temperature at constant volume will be X kJmol-1. X is

(a)  (-Q+RT)       (b) (-Q-RT)        (c) (+Q-RT)         (d) (Q+RT)


70. The most probable reaction of a radical X. with CH2-C(CH3)-COCH3 would give


71. An element crystallizes in a face-centred cubic lattice. Hence its unit cell contains

(a) 14 atoms of the element and 8 of them belong to the unit cell

(b) 14 atoms of the element and 4 of them belong to the unit cell

(c) 8 atoms of the element and 1 of them belong to the unit cell

(d) 8 atoms of the element and 2 of them belong to the unit cell


72. The equilibrium constant for the reaction  is 70 at a certain temperature. Hence, equilibrium constant for the reaction  at the same temperature will be approximately

(a) 1.4 x 10-2      (b) 1.2 x 10-1       (c) 2.0 x 10-4        (d) 2.9 x 10-2


73. The number of optically active compounds in the isomers of C3H5Br3­ is

(a) 1         (b) 2          (c) 3           (d) 4


74. An ammonia bottle in the laboratory is labeled density 0.91 g cm-3, 25% w/w. The molarity of this solution is

(a) 11.5 M          (b) 15 M          (c) 13.4 M           (d) 17 M


75. The concentration which leads to the formation of an ionic liquid at room temperature is

(a) 1-chlorobutane + AlCl3

(b) Ammonium chloride + AlCl3

(c) N-butylpyridinium chloride + AlCl3

(d) NaCl + AlCl3


76.  The enthalpy changes for the below reactions

(a) are the same

(b) are in increasing order

(c) are in decreasing order

(d) cannot be correlated


77. Styrene (Ph-CH=CH2) on polymerization gives polystyrene, which contains chains of the polymer. To make it more rigid the chains are required to be joined at places by certain bridges. It is called cross-linking. The best cross-linking monomer is

(a) ethane     (b) 1,4-divinylbenzene      (c) vinyl chloride      (d) 1,2-dichloroehane


78. The molecule with NON-ZERO dipole moment is

(a) BF3      (b) PCl3       (c) SiCl4       (d) ClF5


79. Hemoglobin is a protein involved in the transport of oxygen from lungs to different tissues. In this protein oxygen binds to

(a) iron-phthalocyanin

(b) iron-porphyrin

(c) cyanocobalamine

(d) copper-porphyrin


80. The ion having a noble gas configuration is

(a) Sc2+      (b) Fe3+       (c) Cr3+       (d) Cu+


81. The structure representing the zwitter-ion form of glycine is


82. Glucose and fructose give the same osazone because

(a) both are hexoses and are epimers of each other

(b) C3, C4 and C5 carbon atoms of both have identical configuration

(c) C1, C2 and C3 carbon atoms of both have identical configuration

(d) both are functional isomers of each other, differing only at C2


83. High purity Germanium is obtained by a technique that is based on

(a) fractional distillation

(b) recrystallisation

(c) fractional crystallization

(d) diffusion


84. The compound in which nickel has the lowest oxidation number is

(a) Ni(CO)4      (b) (CH3COO)2Ni      (c) NiO     (d) NiCl2(PPh3)


85. Paramagnetism is NOT exhibited by

(a) CuSO.5H2O      (b) CuCl2.5H2O       (c) CuI       (d) NiSO4.6H2O


86. The unit of rate constant of a second order reaction with reactants having equal concentration is

(a) mol dm-3 s-1    (b) mol2 dm-6 s-1     (c) dm3 mol-1 s-1      (d) s-1


87. If 0.5 mol of BaCl2 is mixed with 0.2 mol of Na3PO4, the maximum number of moles of Ba3(PO4)2 that can be formed is

(a) 0.1        (b) 0.2         (c) 0.5          (d) 0.7


88. The salt that when added to water will not change its pH is

(a) Na2CO3        (b) NaCl         (c) KCN         (d) NH4Cl


89. The total number of electrons present in 8.0 g of methane is

(a) 4.8 x 1024       (b) 3.01 x 1024        (c) 4.8 x 1025          (d) 3.01 x 1023


90. The molecular orbital with highest energy in a nitrogen molecule is

(a) σ*2S         (b) π2P        (c) σ*2P         (d) π*2P


91. A colourless salt when heated imparts lilac colour to the bunsen flame. It turns red litmus blue. The salt is

(a) Na2CO3       (b) KNO3       (c) NaNO3         (d) K2CO3


92. The proper tautomeric structure for 2-aminopyridine (X) is

93. The metal that CANNOT be displaced from its aqueous solution by zinc is

(a) Cu         (b) Ag         (c) Al           (d) Hg


94. The product obtained in the nitration of 4-methyl-N,N-dimethylaniline in a strongly acidic medium is

(a) 4-methyl-2-nitro-N,N-dimethylaniline

(b) 4,N-dinethyl-2,5-dinitroaniline

(c) 4-methyl-2,5-dinitroaniline

(d) 4-methyl-3-nitro-N,N-dimethylaniline


95. The compound which can be used to initiate a radical polymerization is

96. Boron nitride is isolelectronic with

(a) LiF       (b) CO         (c) (CN)-        (d) AlN


97. The van der waals equation for real gases is (P + a(n/V)2 )(V – nb) = nRT. In the above equation, the terms a(n/V)2 and (-nb) respectively represent the corrections for

(a) intermolecular attractive forces and inelastic collision

(b) intermolecular repulsive forces and high temperatures

(c) intermolecular attractive forces and molecular volumes

(d) deviations in the temperature and pressure


98. The substance that has the lowest boiling point is

(a) HCl        (b) H2S       (c) PH       (d) SiH4


99. IUPAC name for K3[Al(C2O4)3] is

(a) potassium trioxalato aluminate (III)

(b) potassium aluminium oxalate

(c) potassium trioxalate aluminium (III)

(d) potassium trisoxalato aluminium (III)


100. The phenomenon which first suggested that light is emitted in packets (quanta) is

(a) electron diffraction            (b) photoelectric effect

(c) diffraction of light             (d) black body radiation


Read Other Helpful Articles: 

Candidates must also read the links given below 

Anyone Needed NSEC 2009 Answe keys

Stages of Chemistry Olympiad

Trick to Solve Bond Angle Questions

Comments (4)

Hot goIITian

Joined: 16 Jun 2010 18:46:44 IST
Posts: 131
25 Jun 2010 17:09:28 IST
0 people liked this

thanks asish

Hot goIITian

Joined: 16 Jun 2010 18:46:44 IST
Posts: 131
25 Jun 2010 17:10:03 IST
0 people liked this


Blazing goIITian

Joined: 29 Nov 2008 12:50:55 IST
Posts: 1139
26 Jun 2010 16:06:36 IST
0 people liked this

I will need some time to search out the official solutions. (my room is a mess now). and regarding 100. I have no idea about the history of such things

New kid on the Block

Joined: 16 May 2011 06:28:12 IST
Posts: 22
26 Nov 2011 18:25:53 IST
0 people liked this

the answer of ques no. 100 is black body radiation....because that was the first phenomenon which discover that and after that photo electic effect confirmed this phenomenon

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