Practice Questions
3,296 questions across 23 years of JEE Main — find and practise any topic!
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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)
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.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 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
Q54.Given below are two statements : Statement (I) : Corrosion is an electrochemical phenomenon in which pure metal acts as an anode and impure metal as a cathode. Statement (II) : The rate of corrosion is more in alkaline medium than in acidic 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 false but Statement II is true (3) Statement I is true but Statement II is false (4) Both Statement I and Statement II are false 2025 (22 Jan Shift 2) JEE Main Previous Year Paper
Q54.Identify the homoleptic complexes with odd number of d electrons in the central metal : (A) [FeO4]2− (B) [Fe(CN)6]3− (C) [Fe(CN)5NO]2− (D) [CoCl4]2− (E) [Co(H2O)3 F3] Choose the correct answer from the options given below : (1) (A), (B) and (D) only (2) (C) and (E) only (3) (B) and (D) only (4) (A), (C) and (E) only
Q54.An element ' E ′ has the ionisation enthalpy value of 374 kJ mol−1 . ' E ' reacts with elements A, B, C and D with electron gain enthalpy values of −328, −349, −325 and −295 kJ mol−1 , respectively. The correct order of the products EA, EB, EC and ED in terms of ionic character is : (1) ED > EC > EB > EA (2) EA > EB > EC > ED (3) EB > EA > EC > ED (4) ED > EC > EA > EB
Q54.The total number of compounds from below when treated with hot KMnO4 giving benzoic acid is : (1) 6 (2) 3 (3) 5 (4) 4
Q54.When Ethane-1,2-diamine is added progressively to an aqueous solution of Nickel (II) chloride, the sequence of colour change observed will be : (1) Violet → Blue → Pale Blue → Green (2) Pale Blue → Blue → Green → Violet (3) Green → Pale Blue → Blue → Violet (4) Pale Blue → Blue → Violet → Green
Q55.Consider the reaction X2Y( g) = X2( g) + 12 Y2( g) The equation representing correct relationship between the degree of dissociation (x) of X2Y(g) with its equilibrium constant Kp is ______ . Assume x to be very very small. (1) (2) x = 3√2Kpp x = 3√2Kp2p (3) (4) x = 3√Kpp x = 3√Kp2p 2025 (23 Jan Shift 2) JEE Main Previous Year Paper
Q55.Lanthanoid ions with 4f 7 configuration are : (A) Eu2+ (B) Gd3+ (C) Eu3+ (D) Tb3+ (E) Sm2+ Choose the correct answer from the options given below : (1) (A) and (D) only (2) (B) and (C) only (3) (A) and (B) only (4) (B) and (E) only
Q55.Which one of the following, with HBr will give a phenol? 2025 (29 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)
Q55.Given below are two statements : Statement (I) : The first ionization energy of Pb is greater than that of Sn . Statement (II) : The first ionization energy of Ge is greater than that of Si . In the light of the above statements, choose the correct answer from the options given below : (1) Statement I is false but Statement II is true (2) Statement I is true but Statement II is false (3) Both Statement I and Statement II are true (4) Both Statement I and Statement II are false
Q55.Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct? (1) acetophenone < benzaldehyde < p-tolualdehyde (2) benzaldehyde < acetophenone < p- < p- nitrobenzaldehyde nitrobenzaldehyde < p-tolualdehyde (3) p- nitrobenzaldehyde < benzaldehyde < p- (4) acetophenone < p-tolualdehyde < benzaldehyde tolualdehyde < acetophenone < p- nitrobenzaldehyde
Q55.The correct order of stability of following carbocations is : (1) C > B > A > D (2) A > B > C > D (3) B > C > A > D (4) C > A > B > D
Q56.Given below are two statements : Consider the following reaction (1) Both Statement I and Statement II are false (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 true
Q56.The products A and B in the following reactions, respectively are Ag−NO2 AgCN −A ⟷CH3 −CH2 −CH2 −Br → B (1) CH3 −CH2 −CH2 −NO2, CH3 −CH2 −CH2 −CN (2) CH3 −CH2 −CH2 −ONO, CH3 −CH2 −CH2 −NC (3) CH3 −CH2 −CH2 −ONO, CH3 −CH2 −CH2 −CN (4) CH3 −CH2 −CH2 −NO2, CH3 −CH2 −CH2 −NC
Q56.Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. (1) Both ΔH and ΔS are (-ve) (2) ΔH is (-ve) but ΔS is (+ve) (3) ΔH is (+ve) but ΔS is (−ve) (4) Both ΔH and ΔS are (+ve)
Q56. The steam volatile compounds among the following are : (A) (B) (C) (D) Choose the correct answer from the options given below : (1) (B) and (D) Only (2) (A) and (C) Only (3) (A), (B) and (C) Only (4) (A) and (B) Only
Q56.What amount of bromine will be required to convert 2 g of phenol into 2,4,6-tribromophenol? (Given molar mass in gmol−1 of C, H, O, Br are 12, 1, 16, 80 respectively ) (1) 20 .44 g (2) 4.0 g (3) 6.0 g (4) 10.22
Q56.Identify correct statement/s : (A) −OCH3 and −NHCOCH3 are activating group. (B) -CN and -OH are meta directing group. (C) -CN and −SO3H are meta directing group. (D) Activating groups act as ortho - and para directing groups. (E) Halides are activating groups. Choose the correct answer from the options given below : (1) (A) only (2) (A), (B) and (E) only (3) (A) and (C) only (4) (A), (C) and (D) only
Q56.Given below are two statements : Statement I : One mole of propyne reacts with excess of sodium to liberate half a mole of H2 gas. Statement II : Four g of propyne reacts with NaNH2 to liberate NH3 gas which occupies 224 mL at STP. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Statement I is incorrect but Statement II is (2) Both Statement I and Statement II are correct correct (3) Statement I is correct but Statement II is (4) Both Statement I and Statement II are incorrect incorrect 2025 (22 Jan Shift 1) JEE Main Previous Year Paper
Q56. The maximum number of RBr producing 2-methylbutane by above sequence of reactions is ________ - (Consider the structural isomers only) (1) 5 (2) 4 (3) 3 (4) 1
Q56.Identify correct statements : (A) Primary amines do not give diazonium salts when treated with NaNO2 in acidic condition. (B) Aliphatic and aromatic primary amines on heating with CHCl3 and ethanolic KOH form 2025 (28 Jan Shift 2) JEE Main Previous Year Paper carbylamines. (C) Secondary and tertiary amines also give carbylamine test. (D) Benzenesulfonyl chloride is known as Hinsberg's reagent. (E) Tertiary amines reacts with benzenesulfonyl chloride very easily. Choose the correct answer from the options given below : (1) (A) and (B) only (2) (D) and (E) only (3) (B) and (D) only (4) (B) and (C) only