Practice Questions

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. 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

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.The reaction representing the Mond process for metal refining is ______ (1) Δ (2) Δ Ni + 4CO 2K[Au(CN)2] + Zn →K2[Zn(CN)4] + 2 Au →Ni(CO)4 (3) Δ (4) Δ Zr + 2I2 →ZrI4 ZnO + C →Zn + CO Q52.“ A ” obtained by Ostwald's method involving air oxidation of NH3 , upon further air oxidation produces “ B ”. “ B ” on hydration forms an oxoacid of Nitrogen along with evolution of “ A ”. The oxoacid also produces “ A ” and gives positive brown ring test (1) NO2, N2O5 (2) NO2, N2O4 (3) NO, NO2 (4) N2O3, NO2

Q51. The electron in the nth orbit of Li2 + is excited to ( n + 1 ) orbit using the radiation of energy 1 . 47 × 10-17 J (as shown in the diagram). The value of n is ___________ Given : RH = 2 . 18 × 10-18 J

Q51.Which one of the following statements is incorrect ? (1) van Arkel method is used to purify tungsten. (2) The malleable iron is prepared from cast iron by oxidising impurities in a reverberatory furnace. (3) Cast iron is obtained by melting pig iron with (4) Boron and Indium can be purified by zone scrap iron and coke using hot air blast. refining method.

Q51.On complete combustion, 0 . 492 g of an organic compound gave 0 . 792 g of CO2. The % of carbon in the organic compound is (Nearest integer)

Q51.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: In the Ellingham diagram, a sharp change in slope of the line is observed from Mg →MgO at ~1120oC Reason R: There is a large change of entropy associated with the change of state In the light of the above statements, choose the correct answer from the options given below (1) Both A and R are true but R is NOT the correct (2) A is false but R is true explanation of A (3) Both A and R are true and R is the correct (4) A is true but R is false explanation of A

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 set of correct statements is: (i) Manganese exhibits +7 oxidation state in its oxide. (ii) Ruthenium and Osmium exhibit +8 oxidation in their oxides. (iii) Sc shows +4 oxidation state which is oxidizing in nature. (iv) Cr shows oxidising nature in +6 oxidation state. (1) (ii) and (iii) (2) (i), (ii) and (iv) (3) (i) and (iii) (4) (ii), (iii) and (iv)

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.The number of bent-shaped molecule/s from the following is ______ N3- , NO2- , I3- , O3, SO2

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

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. 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.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

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.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.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