Practice Questions
3,296 questions across 23 years of JEE Main — find and practise any topic!
Found 3,296 results
Q60.Propane molecule on chlorination under photochemical condition gives two di-chloro products, " x " and " y ". Amongst " x " and " y ", " x " is an optically active molecule. How many tri-chloro products (consider only structural isomers) will be obtained from " x " when it is further treated with chlorine under the photochemical condition? (1) 2 (2) 5 (3) 4 (4) 3
Q60.Given below are the atomic numbers of some group 14 elements. The atomic number of the element with lowest melting point is : (1) 6 (2) 82 (3) 14 (4) 50
Q61.Match List-I with List-II. List −I cList −II (A) Al3+ < Mg2+ < Na+ < F− (I) IonisationEnthalpy (B) B < C < O < N (II) Metalliccharacter (C) B < Al < Mg < K (III) Electronegativity (D) Si < P < S < Cl (IV ) Ionicradii 2025 (22 Jan Shift 1) JEE Main Previous Year Paper Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(I), (C)-(II), (D)-(III) (2) (A)-(IV), (B)-(I), (C)- (III), (D)-(II) (3) (A)-(III), (B)-(IV), (C)- (II), (D)-(I) (4) (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
Q61.Identify the number of structure/s from the following which can be correlated to D-glyceraldehyde. (1) four (2) one (3) two (4) three
Q61.The product (P) formed in the following reaction is : (1) (2) (3) (4) 2025 (29 Jan Shift 1) JEE Main Previous Year Paper
Q61. For a given reaction R →P, t1/2 is related to [A]0 as given in table. Given: log 2 = 0.30 Which of the following is true? A. The order of the reaction is 1/2. B. If [A]0 is 1 M , then t1/2 is 200√10 min C. The order of the reaction changes to 1 if the concentration of reactant changes from 0.100 M to 0.500 M . D. t1/2 is 800 min for [A]0 = 1.6M Choose the correct answer from the options given below: Options (1) A and C Only (2) A, B and D Only (3) C and D Only (4) A and B Only
Q61.The conditions and consequence that favours the t2ggeg1 configuration in a metal complex are (1) weak field ligand, low spin complex (2) weak field ligand, high spin complex (3) strong field ligand, high spin complex (4) strong field ligand, low spin complex
Q61.The calculated spin-only magnetic moments of K3 [Fe(OH)6] and K4 [Fe(OH)6] respectively are : (1) 3.87 and 4.90 B.M. (2) 4.90 and 5.92 B.M. (3) 4.90 and 4.90 B.M. (4) 5.92 and 4.90 B.M.
Q62.Given below are two statements : Statement (I) : A spectral line will be observed for a 2px →2py transition. Statement (II) : 2Px and 2py are degenerate orbitals. 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 false but Statement II is true (3) Both Statement I and Statement II are false (4) Statement I is true but Statement II is false
Q62.Consider an elementary reaction A(g) + B(g) →C(g) + D(g) If the volume of reaction mixture is suddenly reduced to 1 of its initial volume, the reaction rate will become ' x ' times of the original reaction rate. The 3 value of x is : (1) 3 (2) 19 (3) 9 (4) 13
Q62.Which of the following statements are NOT true about the periodic table? A. The properties of elements are function of atomic weights. B. The properties of elements are function of atomic numbers. C. Elements having similar outer electronic configurations are arranged in same period. D. An element's location reflects the quantum numbers of the last filled orbital. E. The number of elements in a period is same as the number of atomic orbitals available in energy level that is being filled. Choose the correct answer from the options given below: (1) A, C and E Only (2) A and E Only (3) B, C and E Only (4) D and E Only
Q62.Which of the following happens when NH4OH is added gradually to the solution containing 1 M A2+ and 1MB3+ ions? Given : Ksp [A(OH)2] = 9 × 10−10 and Ksp [B(OH)3] = 27 × 10−18 at 298 K . (1) Both A(OH)2 and B(OH)3 do not show (2) A(OH)2 will precipitate before B(OH)3 precipitation with NH4OH (3) B(OH)3 will precipitate before A(OH)2 (4) A(OH)2 and B(OH)3 will precipitate together excess HCHO alkali−
Q62.Match the LIST-I with LIST-II Choose the correct answer from the options given below: (1) A-II, B-III, C-I, D-IV (2) A-III, B-IV, C-I, D-II (3) A-IV, B-I, C-II, D-III (4) A-II, B-III, C-IV, D-I
Q62. HNO3 H2SO4 (1) Ammoniumacetate −−−Identify A, B and C in the given below reaction sequence A → Pb(NO3)2 → B → (2) Acetic acid (3) K2CrO4 (1) PbCl2, PbSO4, PbCrO4 (2) PbS, PbSO4, Pb(CH3COO)2 (3) PbCl2, Pb(SO4)2, PbCrO4 (4) PbS, PbSO4, PbCrO4
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. Match List - I with List - II. Choose the correct answer from the options given below : (1) (A)-(II), (B)-(III), (C)-(IV), (D)-(I) (2) (A)-(II), (B)-(III), (C)-(I), (D)-(IV) (3) (A)-(III), (B)-(II), (C)-(I), (D)-(IV) (4) (A)-(III), (B)-(II), (C)-(IV), (D)-(I)
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.The product B formed in the following reaction sequence is : (1) (2) (3) (4)
Q63.The major product of the following reaction is: CH3CH2CH = O → ? reflux (1) (2) (3) (4)
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.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
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.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