Practice Questions

Q56.The increasing order of pKa for the following phenols is (A) 2,4-Dinitrophenol (B) 4-Nitrophenol (C) 2,4,5-Trimethylphenol (D) Phenol (E) 3-Chlorophenol Choose the correct answer from the option given below : JEE Main 2023 (29 Jan Shift 1) JEE Main Previous Year Paper (1) (A), (E), (B), (D), (C) (2) (A), (B), (E), (D), (C) (3) (C), (D), (E), (B), (A) (4) (C), (E), (D), (B), (A)

Q56. The number of molecules which gives haloform test among the following molecules is :

Q56.The structures of major products A, B and C in the following reaction are sequence. (1) (2) (3) (4)

Q56.The correct order of reactivity of following haloarenes towards nucleophilic substitution with aqueous NaOH is: Choose the correct answer from the options given below: (1) A > B > D > C (2) C > A > D > B (3) D > C > B > A (4) D > B > A > C

Q56.Some amount of dichloromethane CH2Cl2 is added to 671 . 141mL of chloroform CHCl3 to prepare 2 . 6 × 10-3M solution of CH2Cl2DCM. The concentration of DCM is _____ ppm (by mass). JEE Main 2023 (30 Jan Shift 1) JEE Main Previous Year Paper Given: Atomic mass : C = 12; H: 1; Cl = 35 . 5 density of CHCl3 = 1 . 49g cm-3

Q56.The number of correct statement/s involving equilibria in physical processes from the following is ________ (A) Equilibrium is possible only in a closed system at a given temperature. (B) Both the opposing processes occur at the same rate. (C) When equilibrium is attained at a given temperature, the value of all its parameters became equal (D) For dissolution of solids in liquids, the solubility is constant at a given temperature.

Q56.Among the following the number of compounds which will give positive iodoform reaction is _____. (a) 1 -Phenylbutan- 2 -one (b) 2-Methylbutan- 2-ol (c) 3-Methylbutan- 2-ol (d) 1-Phenylethanol (e) 3, 3 -dimethylbutan- 2-one (f) 1-Phenylpropan- 2-ol

Q56.Identify the product formed ( A and E ) (1) (2) (3) (4)

Q56.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R Assertion A:- Butylated hydroxyl anisole when added to butter increases its shelf life. Reason R:- Butylated hydroxyl anisole is more reactive towards oxygen than food. In the light of the above statements, choose the most appropriate answer from the options given below:- (1) Both A and R are correct and R is the correct (2) A is correct but R is not correct. explanation of A. (3) A is not correct but R is correct. (4) Both A and R are correct but R is NOT the correct explanation of A.

Q56.For a reversible reaction A ⇌B, the ΔH forward reaction = 20 kJ mol–1 . The activation energy of the uncatalyzed forward reaction is 300 kJ mol–1 . When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at 27∘C is found to be same as that of the uncatalyzed reaction at 327∘C. The activation energy of the catalysed backward reaction is _______ kJ mol–1 . Q57. 20 mL of 0. 5 M NaCl is required to coagulate 200 mL of As2 S3 solution in 2 hours. The coagulating value of NaCl is ___________.

Q56.At 27°C, a solution containing 2 . 5 g of solute in 250 . 0 mL of solution exerts an osmotic pressure of 400 Pa. The molar mass of the solute is g mol-1 (Nearest integer) (Given : R = 0 . 083 L bar -1 mol-1 )

Q56.Given below are two statements : Statement I : Pure Aniline and other arylamines are usually colourless. Statement II : Arylamines get coloured on storage due to atmospheric reduction. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both Statement I and Statement II are incorrect (2) Both Statement I and Statement II are correct (3) Statement I is correct but Statement II is (4) Statement I is incorrect but Statement II is incorrect correct

Q56. The value of x in compound ‘ D’ is _____

Q56.The magnetic moment is measured in Bohr Magneton (BM). Spin only magnetic moment of Fe in [Fe (H2O)6]3+ and [Fe (CN)6]3− complexes respectively is: (1) 6. 92 B. M. in both (2) 3. 87 B. M. and 1. 732 B. M. (3) 5. 92 B. M. and 1. 732 B. M. (4) 4. 89 B. M. and 6. 92 B. M.

Q57.Mass of Urea NH2CONH2 required to be dissolved in 1000 g of water in order to reduce the vapour pressure of water by 25% is _______ g . (Nearest integer) Given : Molar mass of N, C, O and H are 14, 12, 16 and 1 g mol-1 respectively.

Q57. In the above conversion of compound ( X ) to product ( Y ), the sequence of reagents to be used will be: (1) (i) Br2, Fe (2) (i) Br2(aq) (ii) Fe, H+ (ii) LiAlH4 (iii) LiAlH4 (iii) H3O+ (3) (i) Fe, H+ (4) (i) Fe, H+ (ii) Br2(aq) (ii) Br2(aq) (iii) HNO2 (iii) HNO2 (iv) CuBr (iv) H3 PO2

Q57.A compound ′X′ when treated with phthalic anhydride in presence of concentrated H2 SO4 yields ′Y′. ′Y′ is used as an acid/base indicator. ′X′ and ′Y′ are respectively (1) Anisole, methyl orange (2) Salicylaldehyde, Phenolphthalein (3) Toludine, Phenolphthalein (4) Carbolic acid, Phenolphthalein

Q57. Product [X] formed in the above reaction is: (1) (2) (3) (4)

Q57.Sodium metal crystallises in a body centred cubic lattice with unit cell edge length of 4 Å. The radius of sodium atom is ___ × 10-1Å. (Nearest integer)

Q57.At what pH, given half cell MnO4- (0 . 1M) ∣Mn2 + ( 0 . 001 M ) will have electrode potential of 1 . 282 V ? (Nearest Integer) Given 𝑜 + = 1 . 54 V, 2 . 303RT = 0 . 059 V EMnO4- / Mn2 F

Q57.In a reaction JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper reagents ‘ X ’ and ‘ Y ’ respectively are: (1) (CH3 CO)2O/H+ and CH3 OH /H+, Δ (2) (CH3 CO)2O/H+ and (CH3 CO)2O/H+ (3) CH3 OH /H+, Δ and CH3 OH /H+, Δ (4) CH3 OH /H+Δ and (CH3 CO)2O/H+

Q57.The logarithm of equilibrium constant for the reaction Pd2 + + 4Cl- ⇌PdCl42 - is (Nearest integer) 2 . 303RT Given: = 0 . 06 V F Pd2 + + 2e- ⇌Pd(s) E𝑜= 0 . 83 V ( aq ) PdCl42 - (aq) + 2e- ⇌Pd(s) + 4Cl- (aq) Eo = 0 . 65 V

Q57.Number of compounds giving (i) red colouration with ceric ammonium nitrate and also (ii) positive iodoform test from the following is _________ JEE Main 2023 (25 Jan Shift 2) JEE Main Previous Year Paper

Q57.Match List I with List II. List I List II Reaction Reagents Hoffmann (A) (I) Conc. KOH, Δ Degradation Clemmensen (B) (II) CHCl3, NaOH /H3O+ reduction (C) Cannizzaro reaction (III) Br2, NaOH Reimer-Tiemann (D) (IV) Zn −Hg / HCl reaction (1) (A) - III, (B) - IV, (C) - II, (D) - I (2) (A) - II, (B) - IV, (C) - I, (D) - III (3) (A) - III, (B) - IV, (C) - I, (D) - II (4) (A) - II, (B) - I, (C) - III, (D) - IV

Q57.The mass of NH3 produced when 131. 8 kg of cyclohexane carbaldehyde undergoes Tollen’s test is _____ kg. (Nearest Integer) Molar mass of C = 12 g/ mol N = 14 g/ mol O = 16 g/ mol