Practice Questions
3,214 questions across 23 years of JEE Main — find and practise any topic!
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Q56. The value of x in compound ‘ D’ is _____
Q56.Number of bromo derivatives obtained on treating ethane with excess of Br2 in diffused sunlight is _________
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.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.
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.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.Number of isomeric aromatic amines with molecular formula C8H11N, which can be synthesized by Gabriel Phthalimide synthesis is _____.
Q57.For the given reaction The, total number of possible products formed by tertiary carbocation of A is _______. JEE Main 2023 (13 Apr Shift 1) JEE Main Previous Year Paper
Q57.An aqueous solution of volume 300 cm3 contains 0 . 63 g of protein. The osmotic pressure of the solution at 300 K is 1 . 29 mbar. The molar mass of the protein is gmol-1. Given : R = 0 . 083 LbarK-1 mol-1
Q57.In the following reaction, the total number of oxygen atoms in 𝑋 and 𝑌 is______ Na2O + H2O →2X Cl2O7 + H2O →2Y
Q57.In an electrochemical reaction of lead, at standard temperature, if EPb2o + / Pb = n Volt, then the value of E°Pb2 + / Pb4 + is given by m – xn. The value of x is _______. EPb4o + / Pb (Nearest integer)
Q57.Consider the cell PtsH2g, 1atmH+aq, 1M | Fe3 + aq, Fe2 + aq Pt s When the potential of the cell is 0 . 712 V at 298 K, the ratio Fe2 + / Fe3 + is (Nearest integer) + + + + 2 . 303RT Given: Fe3 + e- = Fe2 , E°Fe3 , Fe2 Pt = 0 . 771 = 0 . 06 V F
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
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.At 298 K, a 1 litre solution containing 10 mmol of Cr2O72 - and 100mmol of Cr3 + shows a pH of 3 . 0. 2 - + 2 . 303RT Given : Cr2O7 →Cr3 ; E0 = 1 . 330 V and F = 0 . 059 V The potential for the half cell reaction is x × 10-3 V . The value of x is _____ .
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.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
Q58.The specific conductance of 0 . 0025M acetic acid is 5 × 10-5 S cm-1 at a certain temperature. The dissociation constant of acetic acid is ___________ × 10-7.(Nearest integer) Consider limiting molar conductivity of CH3COOH as 400 S cm2 mol-1
Q58.A and B are two substances undergoing radioactive decay in a container. The half life of A is 15 min and that of B is 5 min. If the initial concentration of B is 4 times that of A and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? ________min.
Q58.For the adsorption of hydrogen on platinum, the activation energy is 30 kJ mol – 1 and for the adsorption of hydrogen on nickel, the activation energy is 41 . 4 kJ mol – 1 . The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at 300 K is _______ (Nearest integer) Given: In10 = 2 . 3 R = 8 . 3 J K-1 mol-1
Q58.Sea water contains 29 . 25 % NaCl and 19 % MgCl2 by weight of solution. The normal boiling point of the sea water is ∘C (Nearest integer) Assume 100% ionization for both NaCl and MgCl2 Given: KbH2O = 0 . 52 K kg mol-1 Molar mass of NaCl and MgCl2 is 58 . 5 and 95 g mol-1 respectively.
Q58.In Chromyl chloride, the oxidation state of chromium is (+) ___________.
Q58.If compound A reacts with B following first order kinetics with rate constant 2 . 011 × 10-3 s-1. The time taken by A (in seconds) to reduce from 7 g to 2 g will be _____ . (Nearest Integer) log5 = 0 . 698, log7 = 0 . 845, log2 = 0 . 301
Q58.A →B The rate constants of the above reaction at 200 K and 300 K are 0 . 03 min-1 and 0 . 05 min-1 respectively. The activation energy for the reaction is J (Nearest integer) (Given : In 10 = 2 . 3 R = 8 . 3 J K-1 mol-1 log 5 = 0 . 70 log 3 = 0 . 48 log2 = 0 . 30