Practice Questions
1,307 questions across 23 years of JEE Main — find and practise any topic!
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Q52.For hydrogen atom, energy of an electron in first excited state is −3.4eV, K. E. of the same electron of hydrogen atom is xeV . Value of x is ______ ×10−1eV . (Nearest integer)
Q53.For the reaction N2O4( g) ⇌2 NO2( g), Kp = 0. 492 atm at 300 K. Kc for the reaction at same temperature is ______ × 10−2 . (Given : R = 0. 082 L atm mol−1 K−1 )
Q53.When ΔHvap = 30 kJ/mol and ΔSvap = 75 J mol−1 K−1 , then the temperature of vapour, at one atmosphere is ______ K.
Q53.The total number of anti bonding molecular orbitals, formed from 2s and 2p atomic orbitals in a diatomic molecule is _____________.
Q53.The total number of molecular orbitals formed from 2s and 2p atomic orbitals of a diatomic molecule
Q54. In the given TLC, the distance of spot A & B are 5 cm & 7 cm, from the bottom of TLC plate, respectively. Rf value of B is x × 10−1 times more than A . The value of x is ______.
Q54.Using the given figure, the ratio of Rf values of sample A and sample C is x × 10−2 . Value of x is ______
Q54.The heat of combustion of solid benzoic acid at constant volume is −321.30 kJ at 27∘C . The heat of combustion at constant pressure is (−321.30 −xR)kJ , the value of x is _______.
Q54.Standard enthalpy of vapourisation for CCl4 is 30. 5 kJ mol−1 . Heat required for vapourisation of 284 g of CCl4 at constant temperature is __________ kJ. (Given molar mass in gmol−1; C = 12, Cl = 35. 5) Round off your answer to the nearest integer.
Q54.For the reaction at 298 K, 2 A + B →C. ΔH = 400 kJ mol−1 and ΔS = 0.2 kJ mol−1 K−1 . The reaction will become spontaneous above K.
Q54.The total number of 'sigma' and 'Pi' bonds in 2-oxohex-4-ynoic acid is ______ Q55. 2.7 kg of each of water and acetic acid are mixed. The freezing point of the solution will be −x∘C . Consider the acetic acid does not dimerise in water, nor dissociates in water. x = ______ (nearest integer) [Given: Molar mass of water = 18 g mol−1 , acetic acid = 60 g mol−1 KfH2O : 1.86 K kg mol−1 Kf acetic acid: 3.90 K kg mol−1 freezing point: H2O = 273 K, acetic acid = 290 K]
Q54.An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path A →B →C →A as shown in the diagram. The total work done in the process is _____ J.
Q55.Number of optical isomers possible for 2 – chlorobutane ........
Q55.The values of conductivity of some materials at 298 .15 K in Sm−1 are 2 .1 × 103, 1 .0 × 10−16, 1 .2 × 10, 3 .91 , 1 .5 × 10−2, 1 × 10−7, 1 .0 × 103. The number of conductors among the materials is _____.
Q56.One Faraday of electricity liberates x × 10 – 1 gram atom of copper from copper sulphate, x is______.
Q56.Time required for 99.9% completion of a first order reaction is _______ times the time required for completion of 90% reaction.(nearest integer)
Q56.The amount of electricity in Coulomb required for the oxidation of 1 mol of H2O to O2 is ______ × 105C .
Q57.Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is x × 10−3 . Value of x is - (Integer answer)
Q57.The osmotic pressure of a dilute solution is 7 × 105 Pa at 273 K. Osmotic pressure of the same solution at 283 K is _______ × 104 Nm−2 .(Nearest integer)
Q58.In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product is + _______.
Q58.Number of oxygen atoms present in chemical formula of fuming sulphuric acid is ______.
Q59.The rate of first order reaction is 0. 04 mol L−1 s−1 at 10 minutes and 0. 03 mol L−1 s−1 at 20 minutes after initiation. Half life of the reaction is ______ minutes. (Given log 2 = 0. 3010, log 3 = 0. 4771) Round off your answer to the nearest integer.
Q59.Number of ambidentate ligands among the following is ______ NO−2 , SCN−, C2O2−4 , NH3, CN−, SO2−4 , H2O.
Q60.From the vitamins 𝐴, 𝐵1, 𝐵6, 𝐵12, 𝐶, 𝐷, 𝐸 and 𝐾, the number vitamins that can be stored in our body is ______.
Q60.From the given list, the number of compounds with +4 oxidation state of Sulphur SO3, H2 SO3, SOCl2, SF4, BaSO4, H2 S2O7