JAM 2024 Chemistry (CY) Past Paper PDF

JAM 2024 CHEMISTRY (CY) Section A: Q.1 – Q.10 Carry ONE mark each (Multiple Choice Questions) Q.1 The following dipeptide derivative is used as an artificial sweetener: NH2 O...

JAM 2024 CHEMISTRY (CY) Section A: Q.1 – Q.10 Carry ONE mark each (Multiple Choice Questions) Q.1 The following dipeptide derivative is used as an artificial sweetener: NH2 O H HO2C N OCH3 O The constituent -amino acids of this dipeptide are (A) phenylalanine and glutamic acid. (B) phenylalanine and aspartic acid. (C) tyrosine and aspartic acid. (D) tyrosine and glutamic acid. CY 1/48 JAM 2024 CHEMISTRY (CY) Q.2 The suitable reagent combination for the following transformation O O Me Me Me OH is (A) (i) meta-chloroperbenzoic acid (m-CPBA); (ii) NaOH; (iii) aq. HCl (B) (i) OsO4; (ii) aq. HCl (C) (i) I2/NaOH; (ii) aq. HCl (D) (i) dimethyldioxirane (DMDO); (ii) aq. HCl CY 2/48 JAM 2024 CHEMISTRY (CY) Q.3 For the reaction Me Me MeOH/H2O Me Me + KCN Ph Br Ph CN if the concentration of KCN is increased four times, then the rate of the reaction would be (A) unaffected. (B) increased by two times. (C) decreased by four times. (D) increased by four times. CY 3/48 JAM 2024 CHEMISTRY (CY) Q.4 Consider the wavefunction 𝜓(𝑥) = 𝑁[exp(𝑖𝑘𝑥) + exp(−𝑖𝑘𝑥)]. The complex conjugate 𝜓 ∗ (𝑥) is [Given: 𝑁 is the normalization constant; 𝑖 = √−1] (A) 𝑁[exp(−𝑖𝑘𝑥) − exp(𝑖𝑘𝑥)] (B) 𝑁 ∗ [exp(−𝑖𝑘𝑥) − exp(𝑖𝑘𝑥)] (C) 𝑁 ∗ [exp(𝑖𝑘𝑥) + exp(−𝑖𝑘𝑥)] (D) 2𝑁[sin(𝑘𝑥)] CY 4/48 JAM 2024 CHEMISTRY (CY) Q.5 Wavelength of X-rays used in a diffraction experiment is 1.54 Å. X-rays are diffracted from a set of planes with an interplanar spacing of 1.54 Å. Then the angle θ (in degrees) corresponding to the first-order Bragg diffraction is (A) 30º (B) 15º (C) 45º (D) 90º CY 5/48 JAM 2024 CHEMISTRY (CY) Q.6 Identify the reaction for which, at equilibrium, a change in the volume of the closed reaction vessel at a constant temperature will not affect the extent of the reaction. (A) CaCO3 (𝑠) ⇌ CaO(𝑠) + CO2 (𝑔) (B) H2 (𝑔) + I2 (𝑔) ⇌ 2HI(𝑔) (C) 2NO2 (𝑔) ⇌ N2 O4 (𝑔) (D) CO2 (𝑠) ⇌ CO2 (𝑔) CY 6/48 JAM 2024 CHEMISTRY (CY) Q.7 Among [Ti(H2O)6]3+, [NiCl4]2−, [CrO4]2−, and [Mn(H2O)6]2+, the complex that exhibits the largest molar absorptivity in the visible region of the electronic absorption spectrum is (A) [Ti(H2O)6]3+ (B) [NiCl4]2− (C) [CrO4]2− (D) [Mn(H2O)6]2+ CY 7/48 JAM 2024 CHEMISTRY (CY) Q.8 [Co(NH3)5(SO4)]Br and [Co(NH3)5Br]SO4 are examples of (A) ionization isomers. (B) linkage isomers. (C) optical isomers. (D) coordination isomers. CY 8/48 JAM 2024 CHEMISTRY (CY) Q.9 The pair of proteins having heme core is (A) hemoglobin and myoglobin. (B) hemerythrin and myoglobin. (C) hemoglobin and hemocyanin. (D) hemocyanin and hemerythrin. CY 9/48 JAM 2024 CHEMISTRY (CY) Q.10 The shape of SCN¯ is (A) linear. (B) bent. (C) pyramidal. (D) trigonal planar. CY 10/48 JAM 2024 CHEMISTRY (CY) Section A: Q.11 – Q.30 Carry TWO marks each. (Multiple Choice Questions) Q.11 The major product formed in the following reaction H Me  H Me is (A) Me Me (B) Me Me (C) H Me H Me (D) H Me H Me CY 11/48 JAM 2024 CHEMISTRY (CY) Q.12 The major product formed in the following reaction O O Me O Me N Me  O is (A) N Me O O Me (B) Me O O N Me (C) O Me O N Me (D) O O N Me CY 12/48 JAM 2024 CHEMISTRY (CY) Q.13 The major product formed in the following reaction 1. O3, Me2S 2. aq. NaOH is (A) O O (B) CHO (C) O O (D) O O CY 13/48 JAM 2024 CHEMISTRY (CY) Q.14 In the following reaction OTs AcOH/H2O OAc  X optically pure ester X formed product that did not exhibit optical rotation ([α]D = 0) due to the formation of (Note: Ts = para-toluenesulfonyl; Ac = acetyl) (A) cis-1,2-diacetoxycyclohexane. (B) a racemic mixture of trans-1,2-diacetoxycyclohexane. (C) cyclohexene. (D) cyclohexene oxide. CY 14/48 JAM 2024 CHEMISTRY (CY) Q.15 The major products X and Y in the following reactions respectively, are (A) (B) (C) (D) CY 15/48 JAM 2024 CHEMISTRY (CY) Q.16 The major product formed in the following reaction 1. sec-BuLi S 2. Ph Br S 3. HgSO4, aq. H2SO4 4. MeOH, BF3 OEt2 is (A) OMe Ph (B) OMe Ph OMe (C) OMe Ph O (D) OMe Ph S CY 16/48 JAM 2024 CHEMISTRY (CY) Q.17 The acidity of the compounds shown below Me H H H H Me H H Me I II III IV follows the order (A) II > I > III > IV (B) II > IV > III > I (C) I > II > IV > III (D) III > IV > II > I CY 17/48 JAM 2024 CHEMISTRY (CY) Q.18 The major product formed in the following reaction O 1. Br2, aq. KOH Ph NH2 2. aq. HCl is (A) Ph H O (B) Ph H O (C) Br O Ph OH Br (D) O Ph NH2 Br CY 18/48 JAM 2024 CHEMISTRY (CY) Q.19 The ratio of osmotic pressures of aqueous solutions of 0.01 M BaCl2 to 0.005 M NaCl is [Given: Both compounds dissociate completely in water] (A) 3:1 (B) 1:4 (C) 1:1 (D) 3:2 CY 19/48 JAM 2024 CHEMISTRY (CY) Q.20 In the cell reaction P + (𝑎𝑞) + Q(𝑠) → P(𝑠) + Q+ (𝑎𝑞) 𝑜 the EMF of the cell, 𝐸𝑐𝑒𝑙𝑙 is zero. The standard EMF of the cell, 𝐸𝑐𝑒𝑙𝑙 is [Given: Activities of all solids are unity. Activity of P + (𝑎𝑞) is 2 M. Activity of Q+ (𝑎𝑞) is 1 M. 𝑅 = universal gas constant; 𝑇 = temperature; 𝐹 = Faraday constant] (A) 𝑅𝑇 𝐹 (B) 𝑅𝑇 2𝐹 (C) − 𝑅𝑇 ln(2) 𝐹 (D) 𝑅𝑇 ln(2) 𝐹 CY 20/48 JAM 2024 CHEMISTRY (CY) Q.21 Consider photoelectric effect. The number of incident photons is the same for all frequencies. The plot that best describes the dependence of the number of photoelectrons (n) emitted as a function of the incident light frequency (ν) is (A) n (0, 0) (B) n (0, 0) (C) n (0, 0) (D) n (0, 0) CY 21/48 JAM 2024 CHEMISTRY (CY) Q.22 If nitrogen and oxygen gases are at the same temperature, the correct statement according to the kinetic theory of gases is (A) Average kinetic energy of nitrogen and oxygen molecules is inversely proportional to temperature. (B) For nitrogen and oxygen molecules, the root mean square speed is equal to the most probable speed. (C) Average speed of nitrogen molecules is less than the average speed of oxygen molecules. (D) Average kinetic energies of nitrogen and oxygen molecules are equal. CY 22/48 JAM 2024 CHEMISTRY (CY) Q.23 A system undergoes one clockwise cycle from point X back to point X as shown in the figure below: The correct statement about this process is (A) Internal energy of the system decreases at the end of the cycle. (B) Entropy of the system increases at the end of the cycle. (C) System performs work on the surroundings during the cycle. (D) Heat exchanged between system and surroundings is zero during the cycle. CY 23/48 JAM 2024 CHEMISTRY (CY) Q.24 For the reaction shown below 1 CH3Cl Mn2(CO)10 + Na Na[Mn(CO)5] [CH3Mn(CO)5] 2 − NaCl P Q the oxidation states of Mn in P and Q, respectively, are (A) +1 and +1 (B) −1 and +1 (C) −1 and −1 (D) +1 and −1 CY 24/48 JAM 2024 CHEMISTRY (CY) Q.25 The number and nature of d−d transition(s) in the case of Sc2+ in an octahedral crystal field, respectively, are [Ignore spin-orbit coupling and Jahn-Teller distortion.] (A) 1 and spin allowed. (B) 3 and spin allowed. (C) 1 and Laporte allowed. (D) 3 and Laporte allowed. CY 25/48 JAM 2024 CHEMISTRY (CY) Q.26 The d-d transitions in [Mn(H2O)6]2+ and [Ti(H2O)4]3+, respectively, are [Ignore spin-orbit coupling and Jahn-Teller distortion.] (A) symmetry allowed and symmetry forbidden. (B) symmetry forbidden and symmetry allowed. (C) symmetry allowed and symmetry allowed. (D) symmetry forbidden and symmetry forbidden. CY 26/48 JAM 2024 CHEMISTRY (CY) Q.27 A pair of isosteric compounds is (A) H2NBH2 and C2H6 (B) H3N·BH3 and C2H6 (C) B2H6 and C2H6 (D) H3N·BH3 and B2H6 CY 27/48 JAM 2024 CHEMISTRY (CY) Q.28 Zn–C bond polarity in the compounds below Zn Zn Zn I II III follows the order (A) I > II > III (B) III > II > I (C) II > III > I (D) II > I > III CY 28/48 JAM 2024 CHEMISTRY (CY) Q.29 B2 and C2, respectively, are (A) paramagnetic and diamagnetic. (B) diamagnetic and paramagnetic. (C) paramagnetic and paramagnetic. (D) diamagnetic and diamagnetic. CY 29/48 JAM 2024 CHEMISTRY (CY) Q.30 Mobility of ions Li+, Na+, K+, Ag+ in water at 298 K follows the order (A) K+ < Ag+ < Na+ < Li+ (B) Li+ < K+ < Na+ < Ag+ (C) Ag+ < Li+ < K+ < Na+ (D) Li+ < Na+ < Ag+ < K+ CY 30/48 JAM 2024 CHEMISTRY (CY) Section B: Q.31 – Q.40 Carry TWO marks each. (Multiple Select Questions) Q.31 The suitable synthetic route(s) for the following transformation OH OH H H O is/are (A) (i) para-toluenesulfonyl chloride (TsCl), pyridine; (ii) KI; (iii) Mg/Et2O; (iv) CO2; (v) aq. HCl (B) (i) para-toluenesulfonyl chloride (TsCl), pyridine; (ii) KCN; (iii) conc. aq. NaOH, reflux; (iv) aq. HCl (C) (i) CrO3, H2SO4; (ii) SOCl2; (iii) CH2N2; (iv) Ag2O, H2O (D) (i) CrO3, H2SO4; (ii) CH2N2 CY 31/48 JAM 2024 CHEMISTRY (CY) Q.32 The compound(s) which on reaction with CH3MgBr followed by treatment with aqueous NH4Cl would produce 1-methyl-1-phenylethanol as the major product is/are (A) methyl benzoate. (B) phenyl acetate. (C) acetaldehyde. (D) acetophenone. CY 32/48 JAM 2024 CHEMISTRY (CY) Q.33 Among the following, the compound(s) which produce the same osazone as that obtained from D-glucose, when reacted with phenylhydrazine, is/are (A) CHO HO H HO H H OH H OH CH2OH (B) CH2OH C O HO H H OH H OH CH2OH (C) CHO HO H HO H HO H H OH CH2OH (D) CH2OH H OH HO H H OH H OH CH2OH CY 33/48 JAM 2024 CHEMISTRY (CY) Q.34 Among the following, the chiral molecule(s) is/are (A) (B) Cl Me Me Cl (C) CO2H Me (D) Me Me Cl Cl CY 34/48 JAM 2024 CHEMISTRY (CY) Q.35 The correct assumption(s) required to derive Langmuir adsorption isotherm is/are (A) Adsorption is limited to a monolayer on adsorbing surface. (B) All binding sites on adsorbing surface are identical. (C) Adsorption of a molecule on a site enhances binding of other molecules on neighboring sites. (D) Rate of adsorption and rate of desorption are equal at equilibrium. CY 35/48 JAM 2024 CHEMISTRY (CY) Q.36 For one mole of an ideal gas, the correct statement(s) is/are [𝑈 = internal energy; 𝑉 = volume; 𝑇 = temperature; 𝑃 = pressure] (A) 𝜕𝑈 (𝜕𝑉 ) = 0 𝑇 (B) 𝜕𝑈 ( 𝜕𝑇 ) > 0 𝑉 (C) 𝜕𝑃 (𝜕𝑇 ) > 0 𝑉 (D) 𝜕𝑉 (𝜕𝑃 ) > 0 𝑇 CY 36/48 JAM 2024 CHEMISTRY (CY) Q.37 Consider the exothermic chemical reaction O2 (𝑔) + 2H2 (𝑔) ⇌ 2H2 O(𝑔) at equilibrium in a closed container. The correct statement(s) is/are (A) At equilibrium, introduction of catalyst increases product formation. (B) Equilibrium constant decreases with increase in temperature. (C) The equilibrium constant 𝐾𝑃 increases with pressure. (D) Decrease in volume of reaction vessel increases product formation. CY 37/48 JAM 2024 CHEMISTRY (CY) Q.38 Elements and their processes of extraction/purification are given. The correct pair(s) is/are (A) Na; Downs process (B) Ni; Mond process (C) B; Frasch process (D) Al; Bayer process CY 38/48 JAM 2024 CHEMISTRY (CY) Q.39 The correct statement(s) about the ligand substitution/exchange reaction is/are (A) The rate is faster in the case of SF6 than in [AlF6]3−. (B) The rate is faster in the case of [Mg(H2O)6]2+ than in [Sr(H2O)6]2+. (C) The rate of water exchange is faster in the case of [Ni(H2O)6]2+ than in [Co(NH3)5(H2O)]3+. (D) The rate is faster in case of [Cr(H2O)6]2+ than in [Cr(H2O)6]3+. CY 39/48 JAM 2024 CHEMISTRY (CY) Q.40 The stretching frequency of CO in H3BCO is (A) greater than the stretching frequency in free CO. (B) lesser than the stretching frequency in free CO. (C) lesser than the stretching frequency of CO in Fe(CO)5. (D) greater than the stretching frequency of CO in Fe(CO)5. CY 40/48 JAM 2024 CHEMISTRY (CY) Section C: Q.41 – Q.50 Carry ONE mark each. (Numerical Answer Type) Q.41 For the following compound O O H3CO OCH3 the number of signals expected in the 1H NMR spectrum is _________. Q.42 Exhaustive hydrogenation of the following compound under Pd/C generates a saturated hydrocarbon as the product. The number of stereoisomers possible for this product is _______. Q.43 For a zero-order reaction P → Q, the concentration of P becomes half of its initial concentration in 30 minutes after starting the reaction. The concentration of P becomes zero at _______ minutes. (rounded off to the nearest integer) CY 41/48 JAM 2024 CHEMISTRY (CY) Q.44 The magnitude of energy difference between the energy levels 𝑛 = 3 and Xℎ2 𝑛 = 2 of a quantum particle of mass 𝑚 in a box of length L is. 8𝑚L2 Then X = _______. (rounded off to the nearest integer) [Given: ℎ is Planck’s constant and 𝑛 denotes the quantum number] Q.45 The function exp(−2(𝑥 − 1)2 ) attains a maximum at 𝑥 = _______. (rounded off to the nearest integer) Q.46 0.1 M aqueous solution of a weak monobasic acid has pH 2.0. The pKa of the monobasic acid is _______. (rounded off to one decimal place) CY 42/48 JAM 2024 CHEMISTRY (CY) Q.47 The enthalpy change for the reaction 1 C(𝑔) + 2 O2 (𝑔) → CO(𝑔) is _______ kJ per mole of CO(𝑔) produced. (rounded off to one decimal place) [Given: C(𝑔) + O2 (𝑔) → CO2 (𝑔), ΔHrxn = −393.5 kJ per mole of CO2 (𝑔) produced 1 CO2 (𝑔) → CO(𝑔) + 2 O2 (𝑔), ΔHrxn = 283.0 kJ per mole of CO(𝑔) produced] Q.48 The N–O bond order in [NO]− is _______. Q.49 The bond length of CO is 113 pm and its dipole moment (𝜇⃗) is 0.1 D. The charge (in units of electronic charge) on carbon in the CO molecule including its sign is _______. (rounded off to three decimal places) [Given: charge of electron = 1.602 × 10−19 C; 1 D = 3.336 × 10−30 C m] CY 43/48 JAM 2024 CHEMISTRY (CY) Q.50 The magnetic moment of O3 molecule is _______ Bohr magneton (B.M.). (rounded off to the nearest integer) CY 44/48 JAM 2024 CHEMISTRY (CY) Section C: Q.51 – Q.60 Carry TWO marks each. (Numerical Answer Type) Q.51 A reaction of 10.50 g of 1,2-diphenylethane-1,2-dione with conc. NaOH followed by aqueous acidic work-up furnished 8.55 g of a carboxylic acid. The yield of the carboxylic acid in this reaction is _______ %. (rounded off to the nearest integer) Q.52 The specific rotation of an optically pure compound is +75.3 (c 1.0 in CHCl3) at 20 °C. A synthetic sample of the same compound showed a specific rotation of +66.3 (c 1.0 in CHCl3) at 20 °C. The enantiomeric excess (ee) of the synthetic sample is _______ %. (rounded off to the nearest integer) Q.53 A salt QCl of a certain metal Q is electrolyzed to its elements. 40 g of metal Q is formed at an electrode. The volume of Cl2 formed at the other electrode at 1 atm pressure and 298 K is _______ litres. (rounded off to one decimal place) [Given: The gas constant 𝑅 = 0.082 L atm mol−1 K −1, the molar mass of Q is 40 g mol−1 and Cl2 is assumed to be an ideal gas] CY 45/48 JAM 2024 CHEMISTRY (CY) Q.54 If 1 M of a dye in water transmits 50% of incident light at 400 nm, then 2 M of the dye in water transmits _______ % of the incident light at 400 nm. (rounded off to the nearest integer) [Given: Both experiments are performed in the same spectrophotometric cell.] Q.55 A 1.0 L solution is prepared by dissolving 2.0 g of benzoic acid and 4.0 g of sodium benzoate in water. The pH of the resulting solution is _______. (rounded off to one decimal place) Given: Molar mass of benzoic acid is 122 g mol−1 Molar mass of sodium benzoate is 144 g mol−1 p𝐾a of benzoic acid is 4.2 Q.56 The total vapour pressure of an ideal binary liquid mixture of benzene and toluene is 0.3 bar. The vapour pressure of pure benzene is 0.5 bar and that of toluene is 0.2 bar. The mole fraction of benzene in this mixture is _______. (rounded off to two decimal places) CY 46/48 JAM 2024 CHEMISTRY (CY) Q.57 The unit cell of a two-dimensional square lattice with lattice parameter a is indicated by the dashed lines as shown below: The percentage (%) area occupied by the grey circles (of radius r) inside the unit cell is _______. (rounded off to the nearest integer) Q.58 In the oxidation of phosphorus with oxygen, 0.2 mol of P4 produces _______ g of P4O10. (rounded off to one decimal place) [Given: Atomic weight of P = 31; Atomic weight of O = 16] CY 47/48 JAM 2024 CHEMISTRY (CY) Q.59 An element E has three isotopes: 28 14E (abundance 92.21%, atomic mass: 27.977 a.m.u.), 29 14E (abundance 4.70%, atomic mass: 28.976 a.m.u.), and 30 14E (abundance 3.09%, atomic mass: 29.974 a.m.u). The atomic mass of E is _______ a.m.u. (rounded off to three decimal places) Q.60 The wavelength of the γ-ray emitted in 137𝑚 137 56Ba ⇝ 56Ba + γ-ray (0.66 MeV) is _______ Å. (rounded off to three decimal places) [Given: h = 6.626 × 10 −34 J s; c = 2.998 × 108 m s−1; 1 MeV = 1.602 × 10−13 J] CY 48/48