Aieee Chemistry 2004

AIEEE–Past papers CHEMISTRY- UNSOLVED PAPER - 2004

SECTION – A Single Correct Answer Type There are five parts in this question. Four choices are given for each part and one of them is correct. Indicate you choice of the correct answer for each part in your answer-book by writing the letter (a), (b), (c) or (d) whichever is appropriate

01 Problem Which of the following sets of quantum numbers is correct for an electron in 4f orbital ? n = 4, l = 3, m = + 4, s = + 1/2 n = 4, l = 4, m = - 4, s = - 1/2 n = 4, l = 3, m = + 1, s = + 1/2 n = 3, l = 2, m = -2, s = + ½

Problem 02 Consider the ground state of Cr atom (Z = 24). The numbers of electrons with the azimuthally quantum numbers, l = 1 and 2 are, respectively : 12 and 4 12 and 5 16 and 4 16 and 5

Problem 03 Which one of the following ions has the highest value of ionic radius ? Li+ B3+ O2- F-

Problem 04 The wavelength of the radiation emitted when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 x 107 m-1) : 91 mm 192 mm 406 nm 9.1 x 10-8 nm

Problem 05 The correct order of bond angles (smallest first) in H2S, NH3, BF3 and SiH4 is : H2S < SiH4 < NH3 < BF3 NH3 < H2S < SiH4 < BF3 H2S < NH3 < SiH4 < BF3 H2S < NH3 < BF3 < SiH4

Problem 06 Which one of the following sets of ions represents the collection of isoelectromic species K+, Ca2+, Sc3+, Cl- Na+, Ca2+, Sc3+, F- K+, Cl-, Mg2+, Sc3+ Na+, Mg2+, Al3+, Cl- (Atomic numbers F = 9, Cl = 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)

Problem 07 Among Al2O3, SiO2, P2O3 and SO2 the correct order of acid strength is : SO2 < P2O3 < SiO2 < Al2O3 SiO2 < SO2 < Al2O3 < P2O3 Al2O3 < SiO2 < SO2 < P2O3 Al2O3 < SiO2 < P2O3 < SO2

Problem 08 The bond order in NO is 2.5 while that in NO+ is 3. Which of the following statements is true for these two species ? Bond length in NO+ is greater than in NO Bond length in NO is greater than in NO+ Bond length in NO+ is equal to that in NO Bond length is unpredictable

Problem 09 The formation of the oxide ion O2- (g) requires first an exothermic and then an endothermic step as shown below. O(g) + e- = O-(g) ; ∆H0 = - 142 kJmol-1 O(g)- + e- = O2-(g) ; ∆H0 = 844 kJ mol-1 This is because : Oxygen is more electronegative Oxygen has high electron affinity O- ion will tend to resist the addition of another electron O- ion has comparatively larger size than oxygen atom

Problem 10 The sates of hybridization of boron and oxygen atoms in boric acid (H3BO3) are respectively : sp2 and sp2 sp2 and sp3 sp3 and sp2 sp3 and sp3

Problem 11 Which one of the following has the regular tetrahedral structure ? XeF4 SF4 BF [Ni(CN)4]2- (Atomic numbers B = 5, S = 16, Ni = 28, Xe = 54)

Problem 12 Of the following outer electronic configurations of atoms, the highest oxidation state is achieved by which one of them ? (n - 1)d8 ns2 (n - 1)d5 ns1 (n - 1)d3 ns2 (n - 1)d5 ns2

Problem 13 As the temperature is raised from 200C to 400C the average kinetic energy of neon atoms changes by a factor of which of the following ? a. ½ b. c. 313/293 d. 2

Problem 14 The maximum number of 900 angles between bond pair-bond pair of electrons is observed in : dsp3 hybridization sp3d hybridization dsp2 hybridization sp3d2 hybridization

Problem 15 Which one of the following aqueous solutions will exhibit highest boiling point ? 0.01 M Na2SO4 0.01 M KNO3 0.015 M urea 0.015 M glucose

Problem 16 Which among the following factors is the most important in making fluorine the strongest oxidizing agent ? Electron affinity Ionization enthalpy Hydration enthalpy Bond dissociation energy

Problem 17 In van der Waals equation of state of the gas law, the constant ‘b’ is a measure of: Intermolecular repulsions Intermolecular attraction Volume occupied by the molecules Intermolecular collisions per unit volume

Problem 18 The conjugate base of H2PO is : PO43- P2O5 H3PO4 HPO42-

Problem 19 6.02 x 1020 molecules of urea are present in 100 mL of its solution. The concentration of urea solution is : 0.001 M 0.01 M 0.02 M 0.1 M (Avogadro constant, NA = 6.02 x 1023 mol-1)

Problem 20 To neutralize completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H3PO3), the volume of 0.1 M aqueous KOH solution required is : 10 mL 20 mL 40 mL 60 mL

Problem 21 For which of the following parameters the structural isomers C2H5OH and CH3OCH3 would be expected to have the same values ? (Assume ideal behaviour) : Heat of vaporization Vapour pressure at the same temperature Boiling points Gaseous densities at the same temperatures and pressure

Problem 22 Which of the following liquid pairs shows a positive deviation from Raoult’s law ? Water - hydrochloric acid Benzene - methanol Water - nitric acid Acetone - chloroform

Problem 23 Which one of the following statements is false ? Raoult’s law states that the vapour pressure of a component over a solution is proportional to its mole fraction The osmotic pressure ( ) of a solution is given by the equation = MRT, where M is the molarity of the solution The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl2 > KCl > CH3COOH > sucrose Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

Problem 24 What type of crystal defect is indicated in the diagram below ? Na+, Cl-, Na+, Cl-, Na+, Cl- Frenkel defect Schottky defect Interstitial defect Frenkel and Schottky defects

Problem 25 An ideal gas expands in volume from 1 x 10-3 to 1 x 10-2 m3 at 300 K against a constant pressure of 1 x 105 Nm-2. The work done is : - 900 J - 900 kJ 270 kJ 900 kJ

Problem 26 In hydrogen-oxygen fuel cell, combustion of hydrogen occurs to : Generate heat Create potential difference between the two electrodes Produce high purity water Remove adosred oxygen from electrode surfaces

Problem 27 In a first order reaction, the concentration the reactant, decreases frm 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is : 30 min 15 min 7.5 min 60 min

Problem 28 What is the equilibrium expression for the reaction P4(s) + 5O2(g) P4O10(s) ? a. b. c. KC = [O2]5 d.

Problem 29 For the reaction, CO(g) + Cl2 (g) COCl2(g), the Kp/Kc is equal to: a.1/RT b. RT c. d. 1.0

Problem 30 The equilibrium constant for the reactions N2(g) + O2 (g) 2NO(g) at temperature T is 4 x 10-4. The value Kc for the reaction : at the same temperature is : 2.5 x 102 50 4 x 10-4 0.02

Problem 31 The rate equation for the reaction 2A + B-> C is fond to be : are = k [A] [B]. The correct statement in relation to this reaction is that the : Unit of k must be s-1 t1/2 is a constant rate of formation of C is twice the rate of disappearance of A value of k is independent of the initial concentrations of A and B

Problem 32 Consider the following E0 values : Eo Fe3+/Fe2+ = +0.77V EoSn2+/Sn = -0.14 V Under standard conditions the potential for the reaction Sn(s) + 2Fe3+(aq) 2Fe2+ (aq) + Sn2+ (aq) is : 1.68 V 1.40 V 0.91 V 0.63 V

Problem 33 The molar solubility(in mol L-1) of a sparingly soluble salt MX4 is ‘s’ the corresponding solubility product is Ksp. s is given in terms of Ksp by the relation : s = (Ksp/128)1/4 s = (128 Ksp)1/4 s = (256 Ksp)1/5 s = (Ksp/256)1/5

Problem 34 The standard e.m.f. of a cell, involving one electron change is found to be 0.591 V at 250C. The equilibrium constant of the reaction is (F = 96,500 C mol-1, R = 8.314 JK-1 mol-1) : 1.0 x 101 1.0 x 105 1.0 x 1010 1.0 x 1030

Problem 35 The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol-1 respectively. The enthalpy of formation of carbon monoxide per mole is 110.5 kJ -110.5 kJ -676.5 kJ 676.5 kJ

Problem 36 The limiting molar conductivities ^0 for NaCl, KBr and KCl are 126, 152 and 150 S cm2 mol-1 respectively. The ^0 for NaBr is : 128 S cm2 mol-1 176 S cm2 mol-1 278 S cm2 mol-1 302 S cm2 mol-1

Problem 37 In a cell that utilizes the reaction Zn(s) + 2H (aq) -> Zn2+ (aq) + H2 (g) addition of H2SO4 to cathode compartment, will : Lower the E and shift equilibrium to the left Lower the E and shift the equilibrium to the right Increase the E and shift the equilibrium to the right Increase the E and shift the equilibrium to the left

Problem 38 Which one of the following statements regarding helium is incorrect ? It is used to fill gas balloons instead of hydrogen because it is lighter and non-inflammable It is used as a cryogenic agent for carrying out experiments at low temperatures It is used to produce and sustain powerful superconducting magnets It is used in gas-cooled nuclear reactors

Problem 39 Identify the correct statement regarding enzymes : Enzymes are specific biological catalysts that can normally function at very high temperatures (T ~ 1000 K). Enzymes are normally heterogeneous catalysts that are very specific in their action Enzymes are specific biological catalysts that cannot be poisoned Enzymes are specific biological catalysts that possess well defined active sites.

Problem 40 One mole of magnesium nitride on the reaction with an excess of water gives: One mole of ammonia One mole of nitric acid Two moles of ammonia Two moles of nitric acid

Problem 41 Which one of the following ores is best concentrated by froth-floatation method ? Magnetite Cassiterite Galena Malachite

Problem 42 Beryllium and aluminum exhibit many properties which are similar. But, the two elements differ in : Exhibiting maximum covalency in compounds Forming polymeric hydrides Forming covalent halides Exhibiting amphoteric nature in their oxides

Problem 43 Aluminum chloride exists as dimmer, Al2Cl6 in solid state as well as in solution of non-polar solvents such as benzene, when dissolved in water, it gives : Al3+ + 3Cl- [Al(H2O)6]3+ + 3Cl- [Al(OH)6]3- + 3HCl Al2O3 + 6HCl

Problem 44 The soldiers of Napolean army while at Alps during freezing winter suffered a serious problem as regards to the tin buttons of their uniforms. White metallic tin buttons got converted to grey powder. This transformation is related to : A change in the crystalline structure of tin An interaction with nitrogen of the air at very low temperatures A change in the partial pressure of oxygen in the air An interaction with water vapour contained in the humid air

Problem 45 The values for Cr, Mn, Fe and Co are -0.41, + 157, + 0.77 and + 1.97 V respectively. For which one of these metals the change in oxidation state from + 2 to + 3 is easiest ? Cr Mn Fe Co

Problem 46 Excess of KI reacts with CuSO4 solution and the Na2S2O3 solution is added to it. Which of the statements is incorrect for this reaction ? Cu2I2 is formed CuI2 is formed Na2S2O3 is oxidized Evolved I2 is reduced

Problem 47 Among the properties (A) reducing (B) oxidizing (C) complexing, the set of properties shown by CN- ion towards metal species is : A, B B, C C, A A, B, C

Problem 48 The co-ordination number of a central metal atom in a complex is determined by The number of ligands around a metal ion bonded by sigma bonds The number of ligands around a metal ion bounded by pi-bonds The number of ligands around a metal ion bounded by sigma and pi-bonds both The number of only anionic ligands bonded to the metal ion

Problem 49 Which one of the following complexes is an outer orbital complex ? [Fe(CN)6]4- [Mn(CN)6]4- [Co(NH3)6]3+ [Ni(NH3)6]2+ (Atomic numbers Mn = 25, Fe = 36, Co = 27, Ni = 28)

Problem 50 Co-ordination compounds have great importance in biological systems. In this context which of the following statements is incorrect ? Chlorophylls are green pigments in plants and contain calcium Haemoglobin is the red pigment of blood and contains iron Cyanocobalamin is vitamin B12 and contains cobalt Carboxypeptidase-A is an enzyme and contains zinc

Problem 51 Cerkum (Z = 58) is an important member of the lanthanoids. Which of the following statements about cerium is incorrect ? The common oxidation states of cerium are + 3 and + 4 The + 3 oxidation state of cerium is more stable than the + 4 oxidation state The + 4 oxidation state of cerium is not known in solutions Cerium (IV) acts as an oxidizing agent

Problem 52 Which one of the following has largest number of isomers ? [Ru (NH3)4 Cl2]+ [Co (NH3)5Cl]2+ [Ir(PR3)2 H(CO)]2+ [Co(en)2Cl2]+ (R = alkyl group, en = ethylenediamine)

Problem 53 The correct order of magnetic moments (spin only values in B.M.) among the following is [MnCl4]2- > [CoCl4]2- > [Fe(CN6)]4- [MnCl4]2-> [Fe(CN6)]4-> [CoCl4]2- Fe(CN6)]4- > [MnCl4]2- > [CoCl4]2- [Fe(CN6)]4-> [CoCl4]2-> [MnCl4]2- (Atomic numbers Mn = 25, Fe = 26, Co = 27)

Problem 54 Consider the following nuclear reactions : The number of neutrons in he element L is : 142 144 140 146

Problem 55 The half-life of a radioisotope is four hours. If the initial mass of the isotope was 200 g. The mass remaining after 24 hours undecided is : 1.042 g 2.084 g 3.125 g 4.167 g

Problem 56 The compound formed in the positive test for nitrogen with the Lasaigne solution of an organic compound is : Fe4[Fe(CN)6]3 Na3[Fe(CN)6] Fe[Fe(CN)]3 Na4[Fe(CN)6NOS]

Problem 57 The ammonia evolved from the treatment of 0.30 g of an organic compound of the estimation of nitrogen was passed in 100 mL, of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution of complete neutralization. The organic compound is : Acetamide Benzamide Urea Thiourea

Problem 58 Which one of the following has the minimum boiling point ? n-butane 1-butyne 1-butene Isobutene

Problem 59 The IUPAC name of the compound 3,3-dimethyl-1-hydroxy cyclohexane 1,1-dimethyl-3-hydroxy cyclohexane 3,3-dimethyl-1-cyclohexanol 1,1-dimethyl-3-cyclohexanol

Problem 60 Which one of the following does not have sp2hybridised carbon ? Acetone Acetic acid Acetonitrile Acetamide

Problem 61 Which of the following will have a meso-isomer also ? 2-chlorobutane 2,3-dichlorobutane 2, 3-dichloropentane 2- hydroxypropanoic acid

Problem 62 Rate of the reaction Is fastest when Z is : Cl NH2 OC2H5 OCOCH3

Problem 63 Amongst the following compounds, the optically active alkane having lowest molecular mass is :

Problem 64 Consider the acidity of the carboxylic acids: PhCOOH o-NO2C6H4COOH p-NO2C6H4COOH m-NO2C6H4COOH

Problem 65 which of the following is the strongest base ?

Problem 66 Which base is present in RNA but not in DNA ? Uracil Cytosine Guanine Thymine

Problem 67 The compound formed on heating chlorobenzene with chloral in the presence of concentrated sulphuric acid is : Gammexene DDT Freon Hexachloroethane

Problem 68 On mixing ethyl acetate with aqueous sodium chloride, the composition of the resultant solution is : CH3COOC2H5 + NaCl CH3COONa + C2H5OH CH3COCl + C2H5OH + NaOH CH3Cl + C2H5COONa

Problem 69 Acetyl bromide reacts with excess of CH3MgI followed by treatment with a saturated solution of NH4Cl gives : Acetone Acetamide 2-methyl-2-propanol Acetyl iodide

Problem 70 Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon ? Ethyl acetate Acetic acid Acetamide Butan-2-one

Problem 71 Which one of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and acid ? Phenol Benzaldehyde Butananl Benzoic acid

Problem 72 Among the following compounds which can be dehydrated very easily ?

Problem 73 Which of the following compounds is not chiral ? 1-chloropentane 2-chloropentane 1-chloro-2-methyl pentane 3-chloro-2-mehtyl pentane

Problem 74 Insulin production and its action in human body are responsible for the level of diabetes this compound belongs to which of the following categories ? A co-enzyme Ahormone An enzyme An antibiotic

Problem 75 The smog is essentially caused by the presence of : O2 and O3 O2 and N2 Oxides of sulphur and nitrogen O3 and N2

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Aieee Chemistry 2004

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