Practice Questions

Q51.The density of 3M solution of NaCl is 1 . 0 g mL-1. Molality of the solution is ______ × 10-2 m (Nearest integer). Given: Molar mass of Na and Cl is 23 and 35 . 5 g mol-1 respectively.

Q51.The number of paramagnetic species from the following is [Ni(CN)4]2−, [Ni(CO)4], [NiCl4]2− [Fe(CN)6]4−, [Cu (NH3)4]2+ [Fe(CN)6]3− and [Fe (H2O)6]2+

Q51.The incorrect statement from the following for borazine is: (1) It contains banana bonds (2) It can react with water (3) It is a cyclic compound (4) It has electronic delocalization

Q51.The total number of isoelectronic species from the given set is ________. O2−, F–, Al, Mg2+, Na+, O+, Mg, Al3+, F Q52. 30. 4 kJ of heat is required to melt one mole of sodium chloride and the entropy change at the melting point is 28. 4 J K–1 mol–1 at 1 atm. The melting point of sodium chloride is _______ K (Nearest Integer)

Q51.In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at no. of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26 ) (1) V (IV) (2) Mn (VII) (3) Fe (III) (4) Ti (III)

Q51. K2 Cr2 O7 paper acidified with dilute H2 SO4 turns green when exposed to (1) Carbon dioxide (2) Sulphur trioxide (3) Hydrogen sulphide (4) Sulphur dioxide

Q52. KMnO4 oxidises I− in acidic and neutral/faintly alkaline solution, respectively to (1) I2 and IO−3 (2) IO−3 and I2 (3) IO−3 and IO−3 (4) I2 and I2

Q52.Which of the following elements have half-filled f-orbitals in their ground state ? (Given : atomic number Sm −62; Eu = 63; Tb = 65; Gd = 64, Pm = 61) Choose the correct answer from the options given below : (1) A and B only (2) C and D only (3) B and D only (4) A and E only

Q52.Given below are two statements: one is labelled as “Assertion A” and the other is labelled as “Reason R” Assertion A : In the complex Ni(CO)4 and Fe(CO)5 , the metals have zero oxidation state. Reason R : Low oxidation states are found when a complex has ligands capable of π-donor character in addition to the σ -bonding. JEE Main 2023 (06 Apr Shift 2) JEE Main Previous Year Paper In the light of the above statements, choose the most appropriate answer from the options given below (1) A is correct but R is not correct (2) A is not correct but R is correct (3) Both A and R are correct but R is NOT the (4) Both A and R are correct and R is the correct correct explanation of A explanation of A

Q52.Which of the following cannot be explained by crystal field theory? (1) The order of spectrochemical series (2) Magnetic properties of transition metal complexes (3) Colour of metal complexes (4) Stability of metal complexes

Q52.The incorrect statement regarding the reaction given below is (1) The product ‘ B’ formed in the above reaction is p (2) ‘ B’ is N-nitroso ammonium compound -nitroso compound at low temperature (3) The reaction occurs at low temperature (4) The electrophile involved in the reaction is NO+ JEE Main 2023 (12 Apr Shift 1) JEE Main Previous Year Paper

Q52.How many of the following metal ions have similar value of spin only magnetic moment in gaseous state? ________ (Given: Atomic number : V, 23; Cr, 24; Fe, 26; Ni, 28) V3+, Cr3+, Fe2+, Ni3+

Q52.The ratio of sigma and π bonds present in pyrophosphoric acid is

Q52.For independent process at 300 K. Process 𝛥H / kJmol-1 𝛥S / JK-1 A -25 -80 B -22 40 C 25 -50 D 22 20 JEE Main 2023 (24 Jan Shift 1) JEE Main Previous Year Paper The number of non-spontaneous process from the following is _____ .

Q52.One mole of P4 reacts with 8 moles of SOCl2 to give 4 moles of A , x mole of SO2 and 2 moles of B . A, B and x respectively are (1) POCl3, S2 Cl2 and 2 (2) PCl3, S2 Cl2 and 4 (3) PCl3, S2 Cl2 and 2 (4) POCl3, S2 Cl2 and 4

Q52.Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Cu2+ in water is more stable than Cu+ . Reason (R) : Enthalpy of hydration for Cu2+ is much less than that of Cu+ . In the light of the above statements, choose the correct answer from the options given below : (1) Both (A) and (R) are correct and (R) is the (2) (A) is correct but (R) is not correct. 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).

Q52.Correct order of spin only magnetic moment of the following complex ions is: (Given At. No. Fe : 26, Co : 27 ) (1) [FeF6]3−> [CoF6]3−> [Co (C2O4)3]3− (2) [Co (C2O4)3]3−> [CoF6]3−> [FeF6]3− (3) [FeF6]3−> [Co (C2O4)3]3−> [CoF6]3− (4) [CoF6]3−> [FeF6]3−> [Co (C2O4)3]3−

Q52.Solid fuel used in rocket is a mixture of Fe2O3 and Al (in ratio 1 : 2). The heat evolved ( kJ ) per gram of the mixture is _____ (Nearest integer) Given ΔHf0Al2O3 = - 1700 kJ mol-1 ΔHf0Fe2O3 = - 840 kJ mol-1 Molar mass of Fe, AI and O are 56, 27 and 16 g mol – 1 respectively

Q52.The wavelength of an electron of kinetic energy 4 . 50 × 10-29 J is ________ × 10 – 5 m . (Nearest integer) Given: mass of electron is9 × 10 – 31 kg, h = 6 . 6 × 10 – 34 Js

Q52.The sum of lone pairs present on the central atom of the interhalogen IF5 and IF7 is ______

Q52.Zinc reacts with hydrochloric acid to give hydrogen and zinc chloride. The volume of hydrogen gas produced at STP from the reaction of 11 . 5 g of zinc with excess HCl is L (Nearest integer) (Given : Molar mass of Zn is 65 . 4 g mol-1 and Molar volume of H2 at STP = 22 . 7 L )

Q52.Electrons in a cathode ray tube have been emitted with a velocity of 1000 ms-1. The number of following statements which is/are true about the emitted radiation is Given : h = 6 × 10-34Js, me = 9 × 10-31 kg (A ) The deBroglie wavelength of the electron emitted is 666 . 67 nm (B ) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube. (C) The cathode rays start from cathode and move towards anode. (D ) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube..

Q52.Which halogen is known to cause the reaction given below? (1) All halogens (2) Only Bromine (3) Only Iodine (4) Only Chlorine

Q52.The pair of lanthanides in which both elements have high third-ionization energy is: (1) Dy, Gd (2) Lu, Yb (3) Eu, Yb (4) Eu, Gd

Q53.Match List-I with List-II LIST-I LIST-II Coordination Number of unpaired electrons Complex A. [Cr(CN)6]3− I. 0 B. [Fe (H2O)6]2+ II. 3 C. [Co (NH3)6]3+ III. 2 JEE Main 2023 (08 Apr Shift 2) JEE Main Previous Year Paper D. [Ni (NH3)6]2+ IV. 4 Choose the correct answer from the options given below: (1) A-II, B-IV, C-I, D-III (2) A-III, B-IV, C-I, D-II (3) A-II, B-I, C-IV, D-III (4) A-IV, B-III, C-II, D-I