Practice Questions

Q31.Water of mass m gram is slowly heated to increase the temperature from T1 to Tz The change in entropy of the water, given specific heat of water is 1Jkg−1 K−1 , is : (1) m ln ( T2T1 ) (2) zero (3) m ln ( T1T2 ) (4) m (T2 −T1)

Q31.An ideal gas goes from an initial state to final state. During the process, the pressure of gas increases linearly with temperature. A. The work done by gas during the process is zero. B. The heat added to gas is different from change in its internal energy. C. The volume of the gas is increased. D. The internal energy of the gas is increased. E. The process is isochoric (constant volume process) Choose the correct answer from the options given below: (1) E Only (2) A, B, C, D Only (3) A, D, E Only (4) A, C Only →

Q32. Match List - I with List - II. Choose the correct answer from the options given below : (1) (A)-(I), (B)-(III), (C)-(II), (D)-(IV) (2) (A)-(IV), (B)-(II), (C)-(III), (D)-(I) (3) (A)-(II), (B)-(IV), (C)-(I), (D)-(III) (4) (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

Q34.A Carnot engine (E) is working between two temperatures 473 K and 273 K . In a new system two engines - engine E1 works between 473 K to 373 K and engine E2 works between 373 K to 273 K . If η12, η1 and η2 are the efficiencies of the engines E, E1 and E2 , respectively, then (1) η12 = η1η2 (2) η12 ≥η1 + η2 (3) η12 = η1 + η2 (4) η12 < η1 + η2

Q44.The frequency of revolution of the electron in Bohr's orbit varies with n, the principal quantum number as (1) 1 (2) 1 n4 n2 (3) 1 (4) 1 n n3

Q51. List - I List - II (Complex) (Hybridisation & Magnetic characters) (A) [MnBr4]2− (I) d2s3 & diamagnetic Match List - I with List - II. (B) [FeF6]3− (II) sp3 d2 & paramagnetic (C) [Co(C2O4)3]3− (III) sp3 & diamagnetic (D) [Ni(CO)4] (IV) sp3 & paramagnetic Choose the correct answer from the options given below : (1) (A) −(IV), (B) −(II), (C) −(I), (D) −(III) (2) (A) −(III), (B) −(I), (C) −(II), (D) −(IV) (3) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (4) (A) −(III), (B) −(II), (C) −(I), (D) −(IV)

Q51.Given below are two statements : Statement (I) : Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test. Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test. In the light of the above statements, choose the correct anower from the options given below : (1) Statement I is false but Statement II is true (2) Both Statement I and Statement II are true (3) Both Statement I and Statement II are false (4) Statement I is true but Statement II is false

Q51.The carbohydrate "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in ∝-anomeric form Choose the correct answer from the 2025 (24 Jan Shift 1) JEE Main Previous Year Paper options given below: (1) A, D and E Only (2) A, C and D Only (3) A, B and E Only (4) B, D and E Only

Q51.Identify the products [A] and [B], respectively in the following reaction : 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4) −−

Q51.Given below are two statements: Statement I : D-glucose pentaacetate reacts with 2, 4-dinitrophenylhydrazine Statement II : Starch, on heating with concentrated sulfuric acid at 100∘C and 2-3 atmosphere pressure produces glucose. In the light of the above statements, choose the correct answer from the options given below 2025 (28 Jan Shift 1) JEE Main Previous Year Paper (1) Statement I is false but Statement II is true (2) Both Statement I and Statement II are false (3) Both Statement I and Statement II are true (4) Statement I is true but Statement II is false

Q51.Given below are two statements: Statement I: Fructose does not contain an aldehydic group but still reduces Tollen's reagent Statement II: In the presence of base, fructose undergoes rearrangement to give glucose. In the light of the above statements, choose the correct answer from the options given below (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is true but Statement II is false

Q51.Consider the equilibrium CO( g) + 3H2( g) ⇌CH4( g) + H2O( g) If the pressure applied over the system increases by two fold at constant temperature then (A) Concentration of reactants and products increases. (B) Equilibrium will shift in forward direction. (C) Equilibrium constant increases since concentration of products increases. (D) Equilibrium constant remains unchanged as concentration of reactants and products remain same. Choose the correct answer from the options given below : (1) (A), (B) and (C) only (2) (A) and (B) only (3) (A), (B) and (D) only (4) (B) and (C) only

Q52.Consider the following reactions K2Cr2O7 KOH→ [A] H2SO4→ [ B] + K2SO4 The products [A] and [B], −H2O −H2O respectively are : (1) K2CrO4 and CrO (2) K2CrO4 and Cr2O3 (3) K2CrO4 and K2Cr2O7 (4) K2Cr(OH)6 and Cr2O3

Q52.The complex that shows Facial - Meridional isomerism is: (1) 1.[Co(en)2Cl2]+ (2) [Co(en)3]3+ (3) [Co(NH3)3Cl3] (4) [Co(NH3)4Cl2]+ Q53. +2.0v 0.8v −0.5v−−−FeO2−4 → Fe3+ → Fe2+ → Fe0 In the above diagram, the standard electrode potentials are given in volts (over the arrow). The value of EO is FeO2−4 /Fe2+ (1) 2.1 V (2) 1 .7 V (3) 1 .4 V (4) 1 .2 V

Q52.Given below are two statements: Statement I: The conversion proceeds well in the less polar medium. HO− −CH3 −CH2 −CH2 −CH2 −Cl → CH3 −CH2 −CH2 −CH2 −OH + Cl(−) Statement II: The conversion proceeds well in the more polar medium. In the light of the above statements, choose the correct answer from the options given below (1) Both Statement I and Statement II are true (2) Statement I is true but Statement II is false (3) Statement I is false but Statement II is true (4) Both Statement I and Statement II are false

Q52.Density of 3 M NaCl solution is 1.25 g/mL. The molality of the solution is : (1) 1.79 m (2) 2.79 m (3) 2 m (4) 3 m

Q52.Match List - I with List - II. Choose the correct answer from the options given below : (1) (A) −(III), (B) −(I), (C) −(IV), (D) −(II) (2) (A) −(III), (B) −(I), (C) −(II), (D) −(IV) (3) (A) −(IV), (B) −(II), (C) −(III), (D) −(I) (4) (A) −(II), (B) −(IV), (C) −(I), (D) −(III)

Q52. Given below are two statements : Statement (I) : are isomeric compounds.Statement (II) : are functional group isomers. (1) Both Statement (I) and Statement (II) are false. (2) Both Statement (I) and Statement (II) are true. (3) Statement (I) is false but Statement (II) is true. (4) Statement (I) is true but Statement (II) is false. 2025 (28 Jan Shift 2) JEE Main Previous Year Paper

Q52.The incorrect statements regarding geometrical isomerism are : (A) Propene shows geometrical isomerism. (B) Trans isomer has identical atoms/groups on the opposite sides of the double bond. (C) Cis-but-2-ene has higher dipole moment than trans-but-2-ene. (D) 2-methylbut-2-ene shows two geometrical isomers. (E) Trans-isomer has lower melting point than cis isomer. Choose the correct answer from the options given below : (1) (A) and (E) Only (2) (A), (D) and (E) Only (3) (B) and (C) Only (4) (C), (D) and (E) Only

Q52.Both acetaldehyde and acetone (individually) undergo which of the following reactions? A. Iodoform Reaction B. Cannizaro Reaction C. Aldol Condensation D. Tollen's Test E. Clemmensen Reduction Choose the correct answer from the options given below: (1) A, B and D Only (2) C and E Only (3) A, C and E Only (4) B, C and D Only

Q52.J of energy is transferred as heat to 0.5 mol of Argon gas at 298 K and 1.00 atm. The final temperature and the change in internal energy respectively are: Given : R = 8.3 J K−1 mol−1 (1) 378 K and 500 J (2) 368 K and 500 J (3) 348 K and 300 J (4) 378 K and 300 J

Q52.Drug X becomes ineffective after 50% decomposition. The original concentration of drug in a bottle was 16mg/mL which becomes 4mg/mL in 12 months. The expiry time of the drug in months is __________ Assume that the decomposition of the drug follows first order kinetics. (1) 2 (2) 6 (3) 12 (4) 3

Q53.Which of the following oxidation reactions are carried out by both K2Cr2O7 and KMnO4 in acidic medium? A. Γ−→I2 B. S 2−→S C. Fe2+ →Fe3+ D. Γ−→IO3− E. S2O32−→SO42− Choose the correct answer from the options given below: (1) C, D and E Only (2) B, C and D Only (3) A, D and E Only (4) A, B and C Only

Q53.Identify product [A], [B] and [C] in the following reaction sequence. (1) (2) (3) (4)

Q53.The product (A) formed in the following reaction sequence is (1) (2) (3) (4)