Practice Questions

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 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. 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.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.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.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 _____.

Q55.Number of optical isomers possible for 2 – chlorobutane ........

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.One Faraday of electricity liberates x × 10 – 1 gram atom of copper from copper sulphate, x is______.

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.Number of oxygen atoms present in chemical formula of fuming sulphuric acid is ______.

Q58.In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.), the oxidation state of the chromium in the product 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.Oxidation state of Fe(Iron) in complex formed in Brown ring test.

Q60.From the given list, the number of compounds with +4 oxidation state of Sulphur SO3, H2 SO3, SOCl2, SF4, BaSO4, H2 S2O7

Q60.The number of tripeptides formed by three different amino acids using each amino acid once is _______.

Q60.The compound formed by the reaction of ethanal with semicarbazide contains _______ number of nitrogen atoms. ¯

Q61.The area (in sq. units) of the region S = {z ∈C : |z −1| ≤2; (z + ¯z) + i(z −¯z) ≤2, Im(z) ≥0} is (1) 7π (2) 7π 3 4 (3) 17π (4) 3π 8 2

Q61.The sum of all possible values of θ ∈[−π, 2π], for which 1−2i1+i coscosθθ is purely imaginary, is equal (1) 3π (2) 2π (3) 5π (4) 4π