Practice Questions

Q63.Given below are two statements: Statement I: In the oxalic acid vs KMnO4 (in the presence of dil H2SO4 ) titration the solution needs to be heated initially to 60∘C, but no heating is required in Ferrous ammonium sulphate (FAS) vs KMnO4 titration (in the presence of dil H2SO4 ) Statement II: In oxalic acid vs KMnO4 titration, the initial formation of MnSO4 takes place at high temperature, which then acts as catalyst for further reaction. In the case of FAS vs KMnO4 , heating oxidizes Fe2+ into Fe3+ by oxygen of air and error may be introduced in the experiment. 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) 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 1) JEE Main Previous Year Paper

Q63.Given below are two statements : Statement (I) : An element in the extreme left of the periodic table forms acidic oxides. Statement (II) : Acid is formed during the reaction between water and oxide of a reactive element present in the extreme right of the periodic table. In the light of the above statements, choose the correct answer from the options given below : (1) Statement I is true but Statement II is false (2) Both Statement I and Statement II are true (3) Both Statement I and Statement II are false (4) Statement I is false but Statement II is true 2025 (22 Jan Shift 2) JEE Main Previous Year Paper

Q63. The products formed in the following reaction sequence are : (1) (2) , CH3 −CHO , CH3 −COOH (3) (4) , CH3 −CHO

Q64.The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is (1) Mn2+ (2) Cr3+ (3) Ni2+ (4) Ti3+

Q64.How many different stereoisomers are possible for the given molecule? (1) 2 (2) 1 (3) 4 (4) 3

Q64. A2k1 A + A (fast) k−1 The reaction A2 + B2 →2AB follows the mechanism k2 The overall order of the −A + B2 → AB + B (slow) A + B →AB (fast) reaction is : (1) 2 (2) 2.5 (3) 3 (4) 1.5 Q65.1.24 g of AX2 (molar mass 124 g mol−1 ) is dissolved in 1 kg of water to form a solution with boiling point of 100.0156∘C, while 25.4 g∘ of AY2 (molar mass 250 g mol−1 ) in 2 kg of water constitutes a solution with a boiling point of 100.0260∘C. Kb (H2O) = 0.52 K kg mol−1 Which of the following is correct ? (1) AX2 is fully ionised while AY2 is completely (2) AX2 is completely unionised while AY2 is fully unionised. ionised. (3) AX2 and AY2 (both) are completely unionised. (4) AX2 and AY2 (both) are fully ionised.

Q64.Ice at −5∘C is heated to become vapor with temperature of 110∘C at atmospheric pressure. The entropy change associated with this process can be obtained from 2025 (23 Jan Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q64. Residue (A) + HCl (dil) → Compound (B) Structure of residue (A) and compound (B) formed respectively is : (1) (2) (3) (4)

Q64. Choose the correct answer from the options given below : (1) (A)-(III), (B)-(IV), (C)-(II), (D)-(I) (2) (A)-(I), (B)-(III), (C)-(II), (D)-(IV) (3) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (4) (A)-(IV), (B)-(III), (C)-(I), (D)-(II)

Q64.Which of the following statement is true with respect to H2O, NH3 and CH4 ? A. The central atoms of all the molecules are sp3 hybridized. B. The H −O −H, H −N −H and H −C −H angles in the above molecules are 104.5∘, 107.5∘ and 109.5∘ , respectively. C. The increasing order of dipole moment is CH4 < NH3 < H2O. D. Both H2O and NH3 are Lewis acids and CH4 is a Lewis base. E. A solution of NH3 in H2O is basic. In this solution NH3 and H2O act as Lowry-Bronsted acid and base respectively. Choose the correct answer from the options given below: (1) A, B and C Only (2) A, D and E Only (3) C, D and E Only (4) A, B, C and E Only

Q64.Consider a binary solution of two volatile liquid components 1 and 2. x1 and y1 are the mole fractions of component 1 in liquid and vapour phase, respectively. The slope and intercept of the linear plot of 1 vs 1 x1 y1 are given respectively as: P02−P01 (1) P0 P02−P01 (2) P0 2 , 1 , P01 P02 P02 P02 P01−P02 (3) P0 P01−P02 (4) P0 1 , 2 , P02 P02 P01 P02

Q64.First ionisation enthalpy values of first four group 15 elements are given below. Choose the correct value for the element that is a main component of apatite family : (1) 1402 kJ mol−1 (2) 834 kJ mol−1 (3) 1012 kJ mol−1 (4) 947 kJ mol−1

Q64.Assume a living cell with 0.9%(ω/ω) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data upto first decimal place only) The cell will : (1) show no change in volume since solution is (2) shrink since solution is 0.5%(ω/ω) 0.9%(ω/ω) (3) swell up since solution is 1%(ω/ω) (4) None of these

Q65.The structure of the major product formed in the following reaction is : 2025 (24 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q65. The compounds that produce CO2 with aqueous NaHCO3 solution are: A. B. C. D. E. Choose the correct answer from the options given below: (1) A, C and D Only (2) A, B and E Only (3) A and C Only (4) A and B Only

Q65.A vessel at 1000 K contains CO2 with a pressure of 0.5 atm . Some of CO2 is converted into CO on addition of graphite. If total pressure at equilibrium is 0.8 atm , then Kp is : (1) 1.8 atm (2) 0.3 atm (3) 3 atm (4) 0.18 atm

Q65.Which one of the carbocations from the following is most stable? (1) (2) (3) (4) 2025 (24 Jan Shift 1) JEE Main Previous Year Paper

Q65.The ascending order of relative rate of solvolysis of following compounds is : (1) (C) < (B) < (A) < (D) (2) (D) < (A) < (B) < (C) (3) (D) < (B) < (A) < (C) (4) (C) < (D) < (B) < (A) 2025 (23 Jan Shift 2) JEE Main Previous Year Paper

Q65.The alkane from below having two secondary hydrogens is : (1) 4-Ethyl-3,4-dimethyloctane (2) 2,2,3,3-Tetramethylpentane (3) 2,2,4,5-Tetramethylheptane (4) 2,2,4,4-Tetramethylhexane

Q65.Given below are two statements : Statement (I) : On nitration of m-xylene with HNO3, H2SO4 followed by oxidation, 4-nitrobenzene-1,3-dicarboxylic acid is obtained as the major product. Statement (II) : −CH3 group is o/p-directing while −NO2 group is m-directing group. In the light of the above statements, choose the correct answer from the options given below : 2025 (29 Jan Shift 2) JEE Main Previous Year Paper (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

Q65.The incorrect statement among the following is options 1 . (1) PH3 shows lower proton affinity than NH3 . (2) SO2 can act as an oxidizing agent, but not as a reducing agent. (3) PF3 exists but NF5 does not. (4) NO2 can dimerise easily. Q66. 2.8 × 10−3 mol of CO2 is left after removing 1021 molecules from its ' x ' mg sample. The mass of CO2 taken initially is Given: NA = 6.02 × 1023 mol−1 (1) 98 .3 mg (2) 48.2 mg (3) 196 .2 mg (4) 150 .4 mg

Q66.Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction? (1) (2) (3) (4)

Q66. Match List - I with List - II. Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(II), (C)-(I), (D)-(III) (2) (A)-(I), (B)-(II), (C)-(III), (D)-(IV) (3) (A)-(III), (B)-(I), (C)-(IV), (D)-(II) (4) (A)-(II), (B)-(IV), (C)-(III), (D)-(I)

Q66.Choose the correct statements. (A) Weight of a substance is the amount of matter present in it. (B) Mass is the force exerted by gravity on an object. (C) Volume is the amount of space occupied by a substance. (D) Temperatures below 0∘C are possible in Celsius scale, but in Kelvin scale negative temperature is not possible. (E) Precision refers to the closeness of various measurements for the same quantity. Choose the correct answer from the options given below : (1) (A), (D) and (E) Only (2) (C), (D) and (E) Only (3) (A), (B) and (C) Only (4) (B), (C) and (D) Only

Q66.Following are the four molecules "P", "Q", "R" and "S". Which one among the four molecules will react with H −Br(aq) at the fastest rate? (1) R (2) P (3) Q (4) S