Practice Questions

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) : 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.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

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

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.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.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.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. 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.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

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.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.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.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

Q53.At temperature T, compound AB2( g) dissociates as AB2( g) ⇌AB(g) + 12 B2( g) having degree of dissociation x (small compared to unity). The correct expression for x in terms of Kp and p is 2025 (29 Jan Shift 1) JEE Main Previous Year Paper (1) 4√2Kpp (2) 3√2Kpp (3) 3√2 pK2p (4) √Kp

Q53.The effect of temperature on spontaneity of reactions are represented as : (1) (B) and (C) only (2) (B) and (D) only (3) (A) and (D) only (4) (A) and (C) only

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.Given below are two statements : Statement (I): Experimentally determined oxygen-oxygen bond lengths in the O3 are found to be same and the bond length is greater than that of a O = O (double bond) but less than 2025 (24 Jan Shift 2) JEE Main Previous Year Paper that of a single (O −O) bond. Statement (II) : The strong lone pair-lone pair repulsion between oxygen atoms is solely responsible for the fact that the bond length in ozone is smaller than that of a double bond (O = O) but more than that of a single bond (O −O). In the light of the above statements, choose the correct answer from the options given below : (1) Both Statement I and Statement II are false (2) Statement I is false but Statement II is true (3) Statement I is true but Statement II is false (4) Both Statement I and Statement II are true

Q53.The correct order of the following complexes in terms of their crystal field stabilization energies is : (1) [Co(NH3)4]2+ < [Co(NH3)6]2+ < [Co(en)3]3+ < [Co(NH3)6]3+ (2) [Co(NH3)6]2+ < [Co(NH3)6]3+ < [Co(NH3)4]2+ < [Co(en)3]3+ (3) [Co(en)3]3+ < [Co(NH3)6]3+ < [Co(NH3)6]2+ < [Co(NH3)4]2+ (4) [Co(NH3)4]2+ < [Co(NH3)6]2+ < [Co(NH3)6]3+ < [Co(en)3]3+

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

Q53. O2 gas will be evolved as a product of electrolysis of : (A) an aqueous solution of AgNO3 using silver electrodes. (B) an aqueous solution of AgNO3 using platinum electrodes. (C) a dilute solution of H2SO4 using platinum electrodes. (D) a high concentration solution of H2SO4 using platinum electrodes. Choose the correct answer from the options given below : (1) (A) and (C) only (2) (B) and (C) only (3) (A) and (D) only (4) (B) and (D) only

Q53.A liquid when kept inside a thermally insulated closed vessel at 25∘C was mechanically stirred from outside. What will be the correct option for the following thermodynamic parameters ? (1) ΔU < 0, q = 0, w > 0 (2) ΔU = 0, q = 0, w = 0 (3) ΔU > 0, q = 0, w > 0 (4) ΔU = 0, q < 0, w > 0

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

Q54.Which of the following graphs most appropriately represents a zero order reaction ? 2025 (23 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q54. Aman has been asked to synthesise the molecule (x).He thought of preparing the molecule using an aldol condensation reaction. He found a few cyclic alkenes in his laboratory. He thought of performing ozonolysis reaction on alkene to produce a dicarbonyl compound followed by aldol reaction to prepare " x ". Predict the suitable alkene that can lead to the formation of " x ". 2025 (24 Jan Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)