Practice Questions

Q47.In the context of the Hall-Heroult process for the extraction of Al, which of the following statements is false? (1) Na3AlF6 serves as the electrolyte. (2) CO and CO2 are produced in this process. (3) Al2O3 is mixed with CaF2 which lowers the (4) Al3+ is reduced at the cathode to form Al. melting point of the mixture and brings conductivity.

Q47.The reaction 2N2O5(g) →4NO2(g) + O2(g) follows first order kinetics. The pressure of a vessel containing only N2O5 was found to increase from 50 mm Hg to 87.5 mm Hg in 30 min. The pressure exerted by the gases after 60 min. Will be (Assume temperature remains constant) : (1) 106.25 mm Hg (2) 125 mm Hg (3) 116.25 mm Hg (4) 150 mm Hg

Q48.For the equilibrium, A(g) ⇌B(g), Δ H is −40 kJ / mol . If the ratio of the activation energies of the forward (Ef) and reverse (Eb) reactions is 32 then: (1) Ef = 30 kJ / mol, Eb = 70 kJ / mol (2) Ef = 70 kJ / mol, Eb = 30 kJ / mol (3) Ef = 80 kJ / mol, Eb = 120 kJ / mol (4) Ef = 60 kJ / mol, Eb = 100 kJ / mol

Q48.Which among the following is the most reactive? (1) ICl (2) Cl2 (3) Br2 (4) I2

Q48.The following statements relate to the adsorption of gases on a solid surface. Identify the incorrect statement among them: JEE Main 2015 (10 Apr Online) JEE Main Previous Year Paper (1) Entropy of adsorption is negative (2) Enthalpy of adsorption is negative (3) On adsorption decrease in surface energy appears (4) On adsorption, the residual forces on the surface as heat are increased

Q49.In the isolation of metals, calcination process usually results in: (1) Metal oxide (2) Metal carbonate (3) Metal sulphide (4) Metal hydroxide

Q49.Under ambient conditions, which among the following surfactants will form micelles in aqueous solution at lowest molar concentration? ⊕ (1) Br_ (2) CH3 −(CH2)13 −OSO−3 Na+ CH3 (CH2)11 N(CH3)3 ⊕ (3) ⊝ (4) CH3 —(CH2)8— COO⊝Na+ Br CH3 (CH2)15 N(CH3)3

Q49.Which one has the highest boiling point? (1) Xe (2) He (3) Ne (4) Kr

Q50.Match the catalysts to the correct process. Catalyst Process A. TiCl3 i. Wacker process B. PdCl2 ii. Ziegler – Natta polymerisation C. CuCl2 iii. Contact process` D. V2O5 iv. Deacon’s process (1) A →iii , B →i , C →ii , D →iv (2) A →iii , B →ii , C →iv , D →i (3) A →ii , B →i , C →iv , D →iii (4) A →ii , B →iii , C →iv , D →i

Q50.Calamine is an ore of: (1) Iron (2) Copper (3) Aluminium (4) Zinc

Q50.The least number of oxyacids are formed by: (1) Chlorine (2) Fluorine (3) Sulphur (4) Nitrogen

Q51.Which one of the following compounds is not a yellow colored compound ? (1) BaCrO4 (2) Zn2[Fe(CN)6] (3) K3[Co(NO2)6] (4) (NH4)3[As (Mo3O10)4]

Q51.Chlorine water on standing loses its color and forms: JEE Main 2015 (11 Apr Online) JEE Main Previous Year Paper (1) HOCl and HOCl2 (2) HCl only (3) HCl and HClO2 (4) HCl and HOCl

Q51.The cation that will not be precipitated by H2S in the presence of dil HCl is: (1) Co2+ (2) As3+ (3) Pb2+ (4) Cu2+

Q52.An aqueous solution of a salt X turns blood red on treatment with SCN− and blue on treatment with K4[Fe(CN)6] , X also gives a positive chromyl chloride test. The salt X is: (1) FeCl3 (2) Fe(NO3)3 (3) CuCl2 (4) Cu(NO3)2

Q52.The colour of KMnO4 is due to: [where M → metal, L → ligand] (1) σ −σ* transition (2) M →L charge transfer transition (3) d −d transition (4) L →M charge transfer transition

Q52.Which of the following compounds has a P −P Bond? (1) (HPO3)3 (2) H4P2O6 (3) H4P2O7 (4) H4P2O5

Q53.Which molecule/ion among the following cannot act as a ligand in complex compounds? (1) CN− (2) CH4 (3) CO (4) Br−

Q53.The number of geometric isomers that can exist for square planar [Pt(Cl)(py)(NH3)(NH2OH)]+ is (py = pyridine): (1) 6 (2) 2 (3) 3 (4) 4

Q53.Which of the following statements is/are false? (1) Na2Cr2O7 is more soluble than K2Cr2O7 . (2) CrO2−4 is tetrahedral in shape. (3) Na2Cr2O7 is the primary standard in volumetry. (4) Cr2O2−7 has a Cr −O −Cr bond.

Q54.The correct statement on the isomerism associated with the following complex ions. (a) [Ni(H2O)5NH3]2+ (b) [Ni(H2O)4(NH3)2]2+ and (c) [Ni(H2O)3(NH3)3]2+ is: (1) (a) and (b) show only geometrical isomerism (2) (a) and (b) show geometrical and optical isomerism (3) (b) and (c) show geometrical and optical (4) (b) and (c) show only geometrical isomerism isomerism

Q54.Which of the following complex ions has electrons that are symmetrically filled in both t2g and eg orbitals? (1) [Co(NH3)6]2+ (2) [Mn(CN)6]4− (3) [CoF6]3− (4) [FeF6]3−

Q54.The synthesis of alkyl fluorides is best accomplished by: (1) Swarts reaction (2) Free radical fluorination (3) Sandmeyer's reaction (4) Finkelstein reaction

Q55.When concentrated HCl is added to aqueous solution of CoCl2 , its colour changes from reddish pink to deep blue. Which complex ion gives blue colour in reaction? (1) [CoCl6]4− (2) [CoCl6]3− (3) [Co(H2O)6]2+ (4) [CoCl4]2−

Q55. A is : JEE Main 2015 (10 Apr Online) JEE Main Previous Year Paper (1) (2) (3) (4)