NSEC 2011 Question Paper

8/3/2019 NSEC 2011 Question Paper

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Association of Chemistry Teachers

NATIONAL STANDARD EXAMINATION IN CHEMISTRY 2011 -2012

Date of Examination 27th November 2011Time 12.30 to 14.30 Hrs

Instructions to Candidates

01. On the answer sheet, fill up all the entries carefully in the space provided, ONLY IN BLOCKCAPITALS. Use only BLUE or BLACK BALL PEN for making entries and marking answers.Incomplete / incorrect / carelessly filled information may disqualify your candidature.

02. The question paper contains 80 multiple-choice questions. Each question has 4 options, outof which only one is correct. Choose the correct answer and mark a cross in the correspondingbox on the answer sheet as shown below :

03. A correct answer carries 3 marks and 1 mark will be deducted for each wrong answer.

04. All rough work may be done on the blank sheet provided at the end of the question paper.

05. PLEASE DO NOT MAKE ANY MARK OTHER THAN (X) IN THE SPACE PROVIDEDON THE ANSWER SHEET.

Answer sheets are evaluated with the help of a machine. Due to this, CHANGE OF ENTRYIS NOT ALLOWED.

06. Scratching or overwriting may result in wrong score.DO NOT WRITE ANYTHING ON BACK OF ANSWER SHEET.

07. Use of a nonprogrammable calculator is allowed.

08. Periodic table and log table are provided at the end of this question paper.

09. The answers / solutions to this question paper will be available on our website - www.iapt.org.in

by 3 rd December 2011.

Certificates & Awards

i) Certficates to top 10% students of each centre.

ii) Merit certificates to statewise Top 1% students.

iii) Merit certificate and a prize in the form of a book to Nationwise Top 1% students.

10. Result sheets and the "centre top 10%" certificates of NSEC are dispatched to the professorin charge of the centre. Thus you will get your marks from the Professor in charge of yourcentre by January 2012 end.

11. TOP 300 (or so) students are called for the next examination - Indian National ChemistryOlympiad (INChO). Individual letters are sent to these students ONLY.

12. Gold medals will be awarded to TOP 35 students in this entire process.

13. No querries will be entertained in this regard.

Q. a b c d

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NSEC-2011

(1) The number of water molecules present in 0.20g sample of CuSO4.5H2O(Molar mass = 249.7) is

(A)1.2 x 1021

(B) 2.14 x 1021 (C) 2.14 x 10

22(D) 1.2 x 10

23

(2) The group that has the species correctly listed in the order of decreasing radius is

(A) Cu2+

, Cu+, Cu (B) V , V

2+, V

3+(C) F

, Br

, I

(D) B, Be, Li

(3) The number of isomers of dibromobiphenyl (Biphenyl - C6H5-C6H5) is

(A) 8 (B) 10 (C) 12 (D) 14

(4) The enthalpies of decomposition of methane (CH4)(g) and ethane (C2H6)(g) are 400 and 670

kJ.mol1

, respectively. The HC-C in kJmol1

is

(A) 270 (B) 70 (C) 200 (D) 240 mol

(5) The correct formula for hexaaminecobalt (III) nitrate is

(A) [Co3(NH3)](NO3)3 (B) [Co3(NH3)6](NO3)3

(C) [Co(NO3)3].6NH3 (D) [Co(NH3)6](NO3)3

(6) For the reaction PCl3(g) + Cl2(g) = PCl5(g), Kc is 26 at 250oC. Kp at the same

temperature is (R= 8.314 J K1

mol1

)

(A) 4.6 x 10-3

(B) 5.7 x 10-3

(C) 6.0 x 10-3

(D) 8.3 x 10-3

(7) Curved arrows are used in Organic Chemistry to show the movements of electrons in the

mechanism of a reaction. The correct product of the following reaction is


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4

m /z

intensity

1 52 9

4 3

5 7

7 2

(8) Denaturation of protein due to change in pH could be due to

(A) loss of van der Waals interaction (B) hydrophobic interaction

(C) change in ionic interaction (D) breaking ofcovalent bonds

(9) The initial activity of a radionuclide is 9750 counts per min and 975 counts after 5min.

The decay constant of the radionuclide in min1

is about

(A) 0.23 (B) 0.46 (C) 0.69 (D) 0.99

(10) According to VSEPR theory the shape of IF5 molecule will be

(A) tetrahedral (B) trigonal bipyramid (C) square pyramid (D) trigonal planar

(11) The formal charges on the atoms underlined are

C6H5-CN-O

(A) C = 0, N = 1, O = +1 (B) C = 1, N = +1, O = 1

(C) C = 0, N = +1, O = 1 (D) C = +1, N = 0, O = 1

(12) The number of -particles emitted per second by a radioactive element reduces to

6.25% of the original value in 48 days. The half-life period of the element in days is

(A) 3 (B) 8 (C)12 (D) 16

(13) The compound that does not have a bond is

(A) SO2 (B) SF6 (C) O2 (D) SO3

(14) In mass spectrometry a compound is bombarded with high energy electrons to break it into

smaller fragments, which are recorded in the form of their masses (m/z). For example

butane gives fragments like m/z 58, 43, 29, 15, etc. The mass spectrum of an unknown

compound is shown below.


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OH H

O HH

HOOC

CHO

The likely compound among the following is

(A) CH3COCl (B) CH2=CH-CH2CH2OH

(C) CH3CH2COOH (D) CH3COCH2CH3

(15) The solubility of calcium phosphate is S moldm3

. Hence, the solubility product is

(A) S5

(B) 27S3

(C) 54S4

(D) 108S5

(16) The number of valence electrons in an atom with the configuration 1s2

2s2

2p63s

23p

2is

(A) 6 (B) 5 (C) 4 (D) 2

(17) The elevation in boling point of a solution containing 13.44g of CuCl2 in 1 kg of water is(Kb = 0.52 K kg mol

1)

(A) 0.05 (B) 0.10 (C) 0.16 (D) 0.21

(18) The configurations of the carbon atoms C2 and C3 in the following compound arerespectively

(A) R, R (B) S, S (C) R, S (D) S, R

(19) 0.1dm3

of 0.1M acetic acid is titrated against 0.1M NaOH. When 50 cm3

of 0.1M

NaOH are added, the pH of the solution will be ( pKa = 4.74)

(A) 2.37 (B) 4.74 (C) 1.34 (D) 5.74

(20) The IUPAC name of complex [Cu(en)2(H2O)2]+

is

(A) ethylene diamine Cu(II) dihydrate (B) diaquobis(ethylenediamine) Cu(II) ion

(C) diaquobisdiethylamineCu(II) ion (D) diaquobis(ethylenediamine) cuprate (II)


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YES

YES

(D)(C)

(B)(A)

O2N

NO2

NO2

NO2

O

O

O

O

OO

OO

(21) Two protein molecules with the same average molecular mass (molecular weight) can

absorb different amount of ultraviolet radiation due to difference in the content of

(A) tyrosine (B) glutamic acid (C) lysine (D) methionine

(22) Each of the following options contains a structure and a description indicating the existenceof given structure. The correct option for methyl 3-hydroxypent-2-enoate is

(23) Major product of mononitration of the following compound is

(24) If a b c and = = = 90o, the crystal system is

(A) monoclinic (B) triclinic (C) hexagonal (D) orthorhombic

(25) The electronic spectrum of [Ni(H2O)6]++

shows a band at 8500 cm1

due to dd

transition. [Ph4As]2[NiCl4] will have such a transition in cm1 at

(A) 3778 (B) 8500

(C) 4250 (D) 850


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A BCH 3 C CHNaBH4

H2SO4

HgSO4

(26) In the conductometric titration of silver nitrate against KCl, the graph obtained is

(27) The product obtained from the following sequence of reactions is

(A) propanal (B) 2-propanol (C) 1-propanol (D) propane

(28) The compound in which Mn has oxidation state of +3 is

(A) KMnO4 (B) K2[Mn(CN)6] (C) MnSO4 (D) CsMn(SO4)2.12H2O

(29) The SI units of viscocity is

(A) Nsm2 (B) Ns2m (C) Nsm2 (D) Ns2m

(30) If titration of an amino acid present in the solution yielded pI (isoelectric point) value of10.80, the amino acid present in the solution may be

(A) glycine (B) arginine (C) histidine (D) proline

volume of KCl volume of KCl

(B)

Conductance

volume of KCl

(C)

Conductance

volume of KCl

(D)

Conductance

(A)

Conductance


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(D)(C)

(B)(A)

CH 3

Cl

I

CH 3

CH 3

ICl

+ IClLewis acid

(31) In the coordination compound, Na2[Pt(CN)4], the Lewis acid is

(A) [Pt(CN)4]2

(B) Na+

(C) Pt2+

(D) CN

(32) The product (P) of the following reaction is

(33) The correct order of dipole moment for the following molecules is

(A) I = II = III (B) I < II < III (C) I > II > III (D) II < III < I

(34) Lead dissolves most readily in dilute

(A) acetic acid (B) sulphuric acid (C) phosphoric acid (D) sodium hydroxide

(35) The degrees of freedom for the system CaCO3(s) = CaO(s) + CO2(g) are

(A) 1 (B) 2 (C) 3 (D) 4

(36) Semipermeable nature of the cell membrane can be attributed to the presence of

(A) protein and DNA (B) lipid and protein

(C) polysaccharide and lipid (D) DNA and lipid


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(37) The emf of the cell (Zn | ZnSO4 (0.1M) || CdSO4 (0.01M) | Cd) is

(E0Zn2+| Zn = 0.76 V, E0Cd2+| Cd = 0.40 V at 298 K)

(A) +0.33 V (B) +0.36 V (C) +1.13 V (D) 0.36 V

(38) The nitrogen compound formed when Ca(CN)2 reacts with steam or hot water is

(A) N2O (B) NO (C) NO2 (D) NH3

(39) The order of acidities of the H-atoms underlined in the following compounds is in

the order-

(I) Ph- CH2-CH3 (II) Ph-CCH (III) Ph-CH=CH2 (IV)

(A) IV > II > I > III (B) II > IV > III > I (C) III > IV > I > II (D) I > III > II > IV

(40) The half time for a second order reaction with equal concentrations of the reactants is 35seconds. 99% reaction will be completed in

(A) 69s (B) 138s (C) 1733s (D) 3465s

(41) The d orbitals will be split under square planar geometry into

(A) two levels (B) three levels (C) four levels (D) five levels

(42) Rotational spectra of molecules are observed in

(A) UV region (B) Visible region

(C) Near infrared region (D) Far infrared region

(43) The pair of cations which cannot be separated by H2S in a 0.3N acid solution is

(A) Al+++

, Hg++

(B) Bi+++

, Pb++

(C) Zn++

, Cu++

(D) Ni++

, Cd++

(44) Structural features of proteins secreted outside the cells may be stabilised by presence of

(A) hydrogen bond (B) disulfide bond

(C) hydrophobic force (D) phospho-diester bond

(45) The C-O-C bond angle in dimethyl ether is

(A) 109o28

(B) 110

o(C) 120

o(D) 180

o


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(46) Dimethyl glyoxime forms a square planar complex with Ni2+. This complex should be

(A) diamagnetic

(B) paramagnetic having 1 unpaired electron

(C) paramagnetic having 2 unpaired electrons

(D) ferromagnetic

(47) A 0.056 M solution of benzoic acid, C6H5COOH, is titrated with a strong base. [H+] of the

solution when half of the solution is titrated before the equivalence point is (Ka of benzoic

acid = 6.3 x 105

)

(A) 6.3 l05

M (B)1.8 l03

M (C)7.9 l03

M (D)2.6 l02

M

(48) The formula of the isothiocyanate ion is

(A) OCN

(B) SCN

(C) ONC

(D) CN

(49) The compound that is chiral is

(A) 3-methyl-3-hexene (B) 4-chloro-1-methylcyclohexane

(C) 2-phenylpentane (D) 1,3-diisopropylbenzene

(50) The monomer/s of the following polymer is/are

(-CH2-CH(CH3)-CH2-CH(CH3)-CH2-CH(CH3)-)n

(A) ethylene (B) propylene (C) 2-butene (D) ethylene + propylene

(51) Of the interhalogen compounds, ClF3 is more reactive than BrF3, but BrF3 has higher

conductance in the liquid state. The reason is that

(A) BrF3 has higher molecular weight (B) ClF3 is volatile

(C) BrF3 dissociates into BrF2 and BrF4 more easily (D) ClF3 is most reactive

(52) An element X is found to combine with oxygen to form X4O6. If 8.40 g of this element

combine with 6.50 g of oxygen, the atomic weight of the element in grams is

(A) 24.0 (B) 31.0 (C) 50.4 (D) 118.7

(53) Synthesis of RNA in a cell would be affected adversely due to shortage of

(A) sulfate (B) acetate (C) oxalate (D) phosphate


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+ CH 2=CH 2hv

aq NaOHCBA

(lim)Cl2

(ii) H2O

(i) AlCl3

(D)(C)(B)(A)

OH

Cl

O H

O H

OH

OC2H5

O

O

(54) The most abundant element in the earths crust is

(A) aluminium (B) oxygen (C) silicon (D) iron

(55) A beaker is heated from 27C to 127C, the percentage of air originally present in beakerthat is expelled is

(A) 50% (B) 25% (C) 33% (D) 40%

(56) The product (C) of the following sequence of reactions is

(57) The strongest, but the most reactive bond among the following is

(A) C=N (B) C=C (C) CC (D) C=O

(58) Radioactive inert gas is

(A) technetium (B) radon (C) xenon (D) curium

(59) The IUPAC name of the following compound is

(A) 3-methoxy ethylpropanoate (B) ethyl 4-methoxybutanoate

(C) 1,4-diethoxybutane (D) ethoxy 3-methoxybutyrate

(60) Excess of silver nitrate is added to a water sample to determine the amount of chloride ion present in the sample. 1.4 g of silver chloride is precipitated. The mass of chloride ion

present in the sample is

Molar masses (gmol1

): AgNO3 169.91, AgCl 143.25

(A)0.25g (B) 0.35 g (C)0.50 g (D)0.75 g


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(61) The best nucleophile among the following is

(A) H2O (B) CH3SH (C) Cl (D) NH3

(62) The wavelength of a moving body of mass 0.1mg is 3.31 x 1029

m. The kinetic energy of

the body in J would be

(A) 2.0 x 106

(B) 1.0 x 103

(C) 4.0 x 103

(D) 2.0 x 103

(63) Secondary structures could be formed in nucleic acid similar to protein due toformation of

(A) covalent bond (B) ionic bond (C) co-ordinate bond (D) hydrogen bond

(64) The following titration curve represents the titration of a _____acid with a ____base.

(A) strong, strong (B) weak, strong (C) strong, weak (D) weak, weak

(65) The element with the lowest electronegativity is

(A) S (B) I (C) Ba (D) Al

(66) Oxalic acid, H2C2O4, reacts with permanganate ion according to the balanced equation5H2C2O4(aq) + 2MnO4

(aq) + 6H

+(aq) = 2Mn

2+(aq) + 10CO2(g) + 8H2O(l). The volume in

mL of 0.0162M KMnO4 solution required to react with 25.0 mL of 0.022 M H2C2O4

solution is

(A) 13.6 (B)18.5 (C)33.8 (D)84.4

(67) The element that has the highest tendency to catenate is

(A) silicon (B) germanium (C) sulphur (D) boron


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(IV)(III)(II)(I)

(68) The isotope of carbon which is used in carbon dating (a method to estimate the age of an

ancient sample containing carbon) is-(A) carbon-12 (B) carbon-13 (C) carbon-14 (D) carbon-15

(69) Electronic configurations for the atoms of four elements are given below. The

configuration that indicates colourless aqueous solution is

(A) 2,8,14,2 (B) 2,8,16,2 (C) 2,8,18,2 (D) 2,8,13,1

(70) The number of stereoisomers of compound CH3-CH=CH-CH(Br)CH3 is

(A) 2 (B) 3 (C) 4 (D) 6

(71) At 445 C, Kc for the following reaction is 0.020.

2HI(g) = H2(g) + I2(g)

A mixture of H2, I2, and HI in a vessel at 445C has the following concentrations:

[HI] = 2.0M, [H2] = 0.50M and [I2] = 0.10 M. The statement that is true concerning

the reaction quotient, Qc is

(A) Qc = Kc; the system is at equilibrium

(B) Qc is less than Kc; more H2 and I2 will be produced

(C) Qc is less than Kc; more HI will be produced

(D) Qc is greater than Kc; more H2 and I2 will be produced

(72) The order of decreasing stability is

(A) IV>I>II>III (B) I>IV>III>II (C) I>II>IV>III (D) IV>II> I> III

(73) The number of amino acid residues found in a protein that is synthesized from a RNA

molecule with 120 nucleotides is

(A) 120 (B) 80 (C) 40 (D) 60


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+ HCOOH

+ CH 3OH

(74) Hypochlorous acid ionizes as

HOCl(aq) = H+(aq) + OCl

(aq).

OCl(aq) + H2O(l) = HOCl(aq) + OH(aq)

Kafor this reaction at 25C is 3.0 l08

(Kw = 1.0 l014

at 25C)

Hence, Kh for HOCl is

(A) 3.3 l07

(B)3.0 l08

(C)3.0 l06

(D)3.3 l07

(75) Einsteinium has 11 electrons in the 4f subshell. The number of unpaired electrons

in the subshell is-

(A) 3 (B) 4 (C) 7 (D) 11

(76) The order of reactivity of ammonia with the following compounds is

CH2=CHBr (II) CH3-CH2-COCl (III) CH3-CH2-CH2-Cl (IV) (CH3)3C-Br

(A) IV>II>I>III (B) II>IV>III>I (C) III>IV>II>I (D) I>IV>II>III

(77) The freezing point of a solution containing 8.1g of HBr in 100 g of water, assuming the

acid to be 90% ionized is [H=1, Br=80, Kffor water = 1.86 K kg mol1

]

(A) 0.850C (B) -3.53

0C (C) 0

0C (D) -0.35

0C

(78) The reaction of 50% aq KOH on an equimolar mixture of 4-methylbenzaldehyde andformaldehyde followed by acidification gives-


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(79) Iodide ion is oxidized by acidified dichromate ions as shown in this equation.

Cr2O72(aq) + 9I(aq) + 14H+(aq) 2Cr3+(aq) + 3I3(aq) + 7H2O(l). These data wereobtained when the reaction was studied at a constant pH. The order of the reaction with

respect to Cr2O72(aq) and I

(aq) are

(A)first order with respect to both Cr2O72

and I

(B)second order with respect to both Cr2O72

and I

(C)second order with respect to Cr2O72

and first order with respect to I

(D)first order with respect to Cr2O72and second order with respect to I

(80) The number of atoms per unit cell and the number of the nearest neighbours in a body

centred cubic structure are-(A) 4, 12 (B) 2,6 (C) 9, 6 (D) 2, 8

Experiment [Cr2O72-

],M [I-], M Rate,M.s

-1

1 0.0050 0.0125 0.00050

2 0.010 0.0125 0.0010

3 0.0150 0.0250 0.0060


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NSEC 2011 Question Paper