Practice Questions

Q38.Compound A formed in the following reaction reacts with B gives the product C. Find out A and B. (1) A = CH3 −C ≡C−Na+, B = CH3 −CH2 −CH2 −Br (2) A = CH3 −CH = CH2, B = CH3 −CH2 −CH2 −Br (3) A = CH3 −CH2 −CH3, B = CH3 −C ≡CH (4) A = CH3 −C ≡C−Na+, B = CH3 −CH2 −CH3

Q38.If a substance '𝐴' dissolves in solution of a mixture of ' 𝐵' and ' 𝐶 ' with their respective number of moles as 𝑛𝐴, 𝑛𝐵 and 𝑛𝐶, mole fraction of 𝐶 in the solution is: JEE Main 2024 (30 Jan Shift 2) JEE Main Previous Year Paper nC nC (1) (2) nA × nB × nC nA + nB + nC (3) nC (4) nB nA - nB - nC nA + nB

Q38.The correct stability order of the following resonance structures of CH3 −CH = CH −CHO is (1) I > II > III (2) II > III > I (3) II > I > III (4) III > II > I

Q38.How can an electrochemical cell be converted into an electrolytic cell? (1) Applying an external opposite potential lower (2) Reversing the flow of ions in salt bridge. than E0 cell. (3) Applying an external opposite potential greater (4) Exchanging the electrodes at anode and cathode. than E0 cell-

Q38.Relative stability of the contributing structures is : (1) (I) > (II) > (III) (2) (I) > (III) > (II) (3) (II) > (I) > (III) (4) (III) > (II) > (I)

Q38.Chromatographic technique/s based on the principle of differential adsorption is/are A. Column chromatography B. Thin layer chromatography C. Paper chromatography Choose the most appropriate answer from the options given below: (1) B only (2) A only (3) A & B only (4) C only

Q38.Common name of Benzene - 1, 2 - diol is - (1) catechol (2) o-cresol (3) quinol (4) resorcinol

Q38.The difference in energy between the actual structure and the lowest energy resonance structure for the given compound is: (1) electromeric energy (2) resonance energy (3) ionization energy (4) hyperconjugation energy JEE Main 2024 (29 Jan Shift 1) JEE Main Previous Year Paper

Q38. List - I List - II (Pair of compounds) (Isomerism) (A) n-propanol and Isopropanol (I) Metamerism Match List I with List II Choose the (B) Methoxypropane and ethoxyethane (II) Chain Isomerism (C) Propanone and propanal (III) Position Isomerism (D) Neopentane and Isopentane (IV) Functional Isomerism correct answer from the options given below : (1) (A)-(II), (B)-(I), (C)-(IV), (D)-(III) (2) (A)-(III), (B)-(I), (C)-(II), (D)-(IV) (3) (A)-(I), (B)-(III), (C)-(IV), (D)-(II) (4) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Q38.Functional group present in sulphonic acids is : (1) −SO4H (2) −SO3H (3) (4) −SO2 JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper

Q38. Identify (B) and (C) and how are (A) and (C) related ? (1) (2) (3) (4)

Q38.The quantity which changes with temperature is: (1) Molarity (2) Mass percentage (3) Molality (4) Mole fraction

Q38.Thiosulphate reacts differently with iodine and bromine in the reactions given below: 2 S2O2−3 + I2 →S4O2−6 + 2I− Which of the following statement justifies the above dual S2O2−3 + 5Br2 + 5H2O →2SO2−4 + 4Br−+ 10H+ behaviour of thiosulphate? (1) Bromine is a stronger oxidant than iodine (2) Thiosulphate undergoes oxidation by bromine and reduction by iodine in these reaction (3) Bromine is a weaker oxidant than iodine (4) Bromine undergoes oxidation and iodine undergoes reduction in these reactions

Q38. Cyclohexene is _________ type of an organic compound. (1) Benzenoid aromatic (2) Benzenoid non-aromatic (3) Acyclic (4) Alicyclic

Q39.The solution from the following with highest depression in freezing point/lowest freezing point is (1) 180 g of acetic acid dissolved in 1 L of (2) 180 g of acetic acid dissolved in benzene aqueous solution. (3) 180 g of benzoic acid dissolved in benzene (4) 180 g of glucose dissolved in water

Q39.In the given reactions identify the reagent A and reagent B (1) A −CrO3 B −CrO3 (2) A − CrO3 B −CrO2 Cl2 (3) A −CrO2 Cl2 B −CrO2 Cl2 (4) A −CrO2 Cl2 B −CrO3

Q39.The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in the vapour phase. A suitable method for the extraction of these oils from the flowers is: (1) crystallisation (2) distillation under reduced pressure (3) distillation (4) steam distillation

Q39.The set of meta directing functional groups from the following sets is: (1) -CN, - NH2, - NHR, - OCH3 (2) -NO2, - NH2, - COOH, - COOR (3) -NO2, - CHO, - SO3H, - COR (4) -CN, - CHO, - NHCOCH3, - COOR

Q39.Arrange the following elements in the increasing order of number of unpaired electrons in it. (A) Sc (B) Cr (C) V (D) Ti (E) Mn Choose the correct answer from the options given below : (1) (A) < (D) < (C) < (B) < (E) (2) (C) < (E) < (B) < (A) < (D) (3) (A) < (D) < (C) < (E) < (B) (4) (B) < (C) < (D) < (E) < (A)

Q39. Total number of stereo isomers possible for the given structure : (1) 2 (2) 4 (3) 3 (4) 8

Q39.Identify the product A and product B in the following set of reactions. (1) (2) A - CH3CH2CH3 B −CH3CH2CH3 (3) A −CH3CH2CH2 −OH B −CH3CH2CH2 −OH (4)

Q39.Identify A and B in the given chemical reaction sequence : JEE Main 2024 (05 Apr Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q39.Appearance of blood red colour, on treatment of the sodium fusion extract of an organic compound with FeSO4 in presence of concentrated H2 SO4 indicates the presence of element/s (1) Br (2) N (3) N and S (4) S

Q39.Anomalous behaviour of oxygen is due to its (1) Large size and high electronegativity (2) Small size and low electronegativity (3) Small size and high electronegativity (4) Large size and low electronegativity

Q39.Which of the following statements are correct? A. Glycerol is purified by vacuum distillation because it decomposes at its normal boiling point. B. Aniline can be purified by steam distillation as aniline is miscible in water. C. Ethanol can be separated from ethanol water mixture by azeotropic distillation because it forms azeotrope. D. An organic compound is pure, if mixed M.P. is remained same. Choose the most appropriate answer from the options given below : (1) A, B, C only (2) A, C, D only (3) A, B, D only (4) B, C, D only