Practice Questions

Q54.When 0. 15 g of an organic compound was analyzed using Carius method for estimation of bromine, 0. 2397 g of AgBr was obtained. The percentage of bromine in the organic compound is _________.(Nearest integer) [Atomic mass : Silver = 108, Bromine = 80]

Q54.The pressure exerted by a non-reactive gaseous mixture of 6. 4 g of methane and 8. 8 g of carbon dioxide in a 10 L vessel at 27°C is _____ kPa. (Round off to the Nearest Integer). [Assume gases are ideal, R = 8. 314 J mol−1 K−1 Atomic masses: C : 12. 0 u, H : 1. 0 u, O : 16. 0 u ]

Q54.The solubility of CdSO4 in water is 8. 0 × 10−4 mol L−1 . Its solubility in 0. 01M H2 SO4 solution is ___ ×10−6 mol L−1 (Round off to the Nearest integer) (Assume that solubility is much less than 0. 01 M ) Q55. 10. 0 ml of Na2 CO3 solution is titrated against 0. 2 M HCl solution. The following values were obtained in 5 readings. 4. 8 ml, 4. 9 ml, 5. 0 ml, 5. 0 ml and 5. 0 ml JEE Main 2021 (18 Mar Shift 2) JEE Main Previous Year Paper Based on these readings, and convention of titrimetric estimation of concentration of Na2 CO3 solution is ___ mM. (Round off to the Nearest integer)

Q54.At 298 K, the enthalpy of fusion of a solid X is 2 . 8 kJ mol-1 and the enthalpy of vaporisation of the liquid X is 98 . 2 kJ mol-1. The enthalpy of sublimation of the substance X in kJ mol-1 is ______. (in nearest integer)

Q54.The number of moles of NH3, that must be added to 2 L of 0. 80 MAgNO3 in order to reduce the concentration of Ag+ ions to 5. 0 × 10−8M(Kformation for [Ag (NH3)2]+ = 1. 0 × 108) is __________. (Nearest integer) [Assume no volume change on adding NH3 ]

Q54.Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is ___ . (Integer answer) JEE Main 2021 (25 Feb Shift 2) JEE Main Previous Year Paper (A) Li (B) Na (C) Rb (D) Cs

Q54.The transformation occurring in Duma's method is given below y y z y C2H7 N + 2x + 2CuO →xCO2 + 2H2O + 2 N2 + 2x + 2Cu The value of y is (Integer answer)

Q54.For the reaction C2H6 →C2H4 + H2 the reaction enthalpy ΔrH in kJmol−1 is (Round off to the Nearest Integer). [Given : Bond enthalpies in kJmol−1 : C −C : 347, C = C : 611; C −H : 414, H −H : 436]

Q54.An empty LPG cylinder weighs 14 . 8 kg. When full, it weighs 29 . 0 kg and shows a pressure of 3 . 47 atm . In the course of use at ambient temperature, the mass of the cylinder is reduced to 23 . 0 kg . The final pressure inside the cylinder is _____ atm. (Nearest integer) (Assume LPG to be an ideal gas) JEE Main 2021 (01 Sep Shift 2) JEE Main Previous Year Paper

Q55.The number of acyclic structural isomers (including geometrical isomers) for pentene are

Q55.The solubility product of PbI2 is 8. 0 × 10−9. The solubility of lead iodide in 0. 1 molar solution of lead nitrate is x × 10−6 mol /L. The value of x is _________ (Rounded off to the nearest integer) [Given √2 = 1. 41]

Q55.Assuming that Ba(OH)2 is completely ionised in aqueous solution under the given conditions the concentration of H3O+ ions in 0. 005M aqueous solution of Ba(OH)2 at 298 K is _________ ×10−12 mol L−1. (Nearest integer) Q56. 0. 8 g of an organic compound was analysed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then....... mL of 1M H2 SO4 would have been neutralized by the ammonia evolved during the analysis. JEE Main 2021 (25 Jul Shift 2) JEE Main Previous Year Paper

Q55. KBr is doped with 10−5 mole percent of SrBr2 The number of cationic vacancies in 1 g of KBr crystal is 1014 . (Round off to the Nearest Integer). [Atomic Mass : K = 39. 1u, Br = 79. 9u, NA = 6. 023 × 1023]

Q55.For the reaction 2NO2 ( 𝑔) ⇌N2O4 ( g ) , when ΔS = - 176 . 0 J K-1 and ΔH = - 57 . 8 kJ mol-1 the magnitude of ΔG at 298 K for the reaction is _____ kJmol-1. (Nearest integer)

Q55.The unit cell of copper corresponds to a face centered cube of edge length 3. 596 Å with one copper atom at each lattice point. The calculated density of copper in kg /m3 is ___ . [Molar mass of Cu : 63. 54 g; Avogadro Number = 6. 022 × 1023 J]

Q55.Dichromate ion is treated with base, the oxidation number of Cr in the product formed is Q56. 224 mL of SO2(g) at 298 K and 1 atm is passed through 100 mL of 0. 1 M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution (assuming the solution is dilute) ( P°(H2O)= 24 mm of Hg ) is x × 10−2 mm of Hg the value of x is (Integer answer)

Q55. PCl5 ⇌PCl3 + Cl2 Kc = 1. 844 3. 0 moles of PCl5 is introduced in a 1L closed reaction vessel at 380 K. The number of moles of PCl5 at equilibrium is — × 10−3 (Round off to the Nearest Integer)

Q55.Diamond has a three dimensional structure of C atoms formed by covalent bonds. The structure of diamond has face centred cubic lattice where 50% of the tetrahedral voids are also occupied by carbon atoms. The number of carbon atoms present per unit cell of diamond is ________.

Q55.For the reaction A + B ⇌2C the value of equilibrium constant is 100 at 298 K. If the initial concentration of all the three species is 1 M each, then the equilibrium concentration of C is x × 10-1 M. The value of x is _______. (Nearest integer)

Q55.Data given for the following reaction is as follows : FeO(s) + C(graphite) ⟶Fe(s) + CO(g) Substance ΔfH°(kJmol−1) ΔS°(Jmol−1 K−1) FeO(s) −266. 3 57. 49 C(graphite) 0 5. 74 Fe(s) 0 27. 28 CO(g) −110. 5 197. 6 The minimum temperature in K at which the reaction becomes spontaneous is_____.(Integer answer)

Q55.In basic medium CrO2−4 oxidises S2O2−3 to form SO4 2− and itself changes into Cr (OH)−4 .The volume of 0. 154 MCrO2−4 required to react with 40 mL of 0. 25 MS2 O3 2− is _____ mL. (Rounded-off to the nearest integer)

Q55.In Duma's method of estimation of nitrogen, 0. 1840 g of an organic compound gave 30 mL of nitrogen collected at 287 K and 758 mm of Hg pressure. The percentage composition of nitrogen in the compound is ______. (Round off to the Nearest Integer). [Given : Aqueous tension at 287 K = 14 mm of Hg ]

Q55.The molarity of the solution prepared by dissolving 6. 3 g of oxalic acid (H2C2O4 ⋅2H2O) in 250 mL of water in mol L−1 is x × 10−2. The value of x is _________ . (Nearest integer) [Atomic mass : H : 1. 0, C : 12. 0, 0 : 16. 0 J]

Q55.Two salts A2X and MX have the same value of solubility product of 4. 0 × 10−12 . The ratio of their molar solubilizes i.e. S(A2X) S(MX) = ________. (Round off to the Nearest Integer). Q56. 2 MnO−4 + bC2 O2−4 + cH+ →xMn2+ + yCO2 + zH2 O If the above equation is balanced with integer coefficients, the value of c is _______ . (Round off to the Nearest Integer). o

Q55.When 10 mL of an aqueous solution of KMnO4 was titrated in acidic medium, equal volume of 0. 1M of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of KMnO4 in grams per litre is _______ ×10−2. (Nearest integer) [Atomic mass of K = 39, Mn = 55, O = 16 ]