Practice Questions

Q47. Cu+/Cu = +0.52 V, Fe3+/Fe2+ = +0.77 V, Electrode potentials (E∘) are given below : 1 Based on the above potentials, strongest I2( s)/I−= +0.54 V, 2 Ag+/Ag = +0.88 V. oxidizing agent will be : JEE Main 2013 (09 Apr Online) JEE Main Previous Year Paper (1) Cu+ (2) Fe3+ (3) Ag+ (4) I2

Q47.A molecule M associates in a given solvent according to the equation M ⇌(M)n . For a certain concentration of M, the van't Hoff factor was found to be 0.9 and the fraction of associated molecules was 0.2. The value of n is: (1) 3 (2) 5 (3) 2 (4) 4

Q48.The Gibbs energy for the decomposition of Al2O3 at 500 C is as follows : 2 3 Al2O3 →43 Al + O2, ΔrG = +940 kJ mol−1 The potential difference needed for the electrolytic reduction of aluminium oxide at 500∘C should be at least : JEE Main 2013 (25 Apr Online) JEE Main Previous Year Paper (1) 4.5 V (2) 3.0 V (3) 5.0 V (4) 2.5 V

Q48.Flocculation value of BaCl2 is much less than that of KCl for sol A and flocculation value of Na2SO4 is much less than that of NaBr for sol B. The correct statement among the following is : (1) Both the sols A and B are negatively charged. (2) Sol A is positively charged and Sol B is negatively charged. (3) Both the sols A and B are positively charged. (4) Sol A is negatively charged and sol B is positively charged.

Q48.Which has trigonal bipyramidal shape ? (1) XeOF4 (2) XeO3 (3) XeO3 F2 (4) XeOF2

Q48.The instantaneous rate of disappearance of MnO−4 ion in the following reaction is 4.56 × 10−3Ms−1 2MnO−4 + 10I−+ 16H+ →2Mn2+ + 5I2 + 8H2O The rate of appearance I2 is : (1) 4.56 × 10−4Ms−1 (2) 1.14 × 10−2Ms−1 (3) 1.14 × 10−3Ms−1 (4) 5.7 × 10−3Ms−1

Q48.Which of the following exists as covalent crystals in the solid state ? (1) Sulphur (2) Phosphorus (3) Iodine (4) Silicon

Q49.In Goldschmidt aluminothermic process which of the following reducing agents is used : (1) calcium (2) coke (3) Al-powder (4) sodium JEE Main 2013 (22 Apr Online) JEE Main Previous Year Paper

Q49.Four successive members of the first row of transition elements are listed below with atomic numbers. Which one of them is expected to have the highest Eo value? M3+/M2+ (1) Fe (Z = 26) (2) Co (Z = 27) (3) Cr (Z = 24) (4) Mn (Z = 25)

Q49.The migration of dispersion medium under the influence of an electric potential is called : (1) Cataphoresis (2) Electroosmosis (3) Electrophoresis (4) Sedimentation

Q49.When a small amount of KMnO4 is added to concentrated H2SO4 , a green oily compound is obtained which is highly explosive in nature. Compound may be : (1) MnSO4 (2) Mn2O7 (3) MnO2 (4) Mn2O3 JEE Main 2013 (23 Apr Online) JEE Main Previous Year Paper

Q49.A solution of copper sulphate (CuSO4) is electrolysed for 10 minutes with a current of 1.5 amperes. The mass of copper deposited at the cathode (at. mass of Cu = 63u ) is : (1) 0.3892 g (2) 0.2938 g (3) 0.2398 g (4) 0.3928 g

Q50.A radioactive isotope having a half - life period of 3 days was received after 12 days. If 3 g of the isotope is left in the container, what would be the initial mass of the isotope ? (1) 12 g (2) 36 g (3) 48 g (4) 24 g

Q50.Oxidation state of sulphur in anions SO2−3 , S2O2−4 and S2O2−6 increases in the orders : (1) S2O2−6 < S2O2−4 < SO2−3 (2) SO2−6 < S2O2−4 < S2O2−6 (3) S2O2−4 < SO2−3 < S2O2−6 (4) S2O2−4 < S2O2−6 < SO2−3

Q50.Identify incorrect statement : (1) Cu2O is colourless. (2) Copper (I) compounds are colourless except when colour results from charge transfer. (3) Copper (I) compounds are diamagnetic. (4) Cu2 S is black.

Q50.Calcination is the process in which: (1) ore is heated above its melting point to expel (2) ore is heated below its melting point to expel H2O or CO2 or SO2 volatile impurities (3) ore is heated above its melting point to remove (4) ore is heated below its melting point to expel S, As and Sb as SO2, As2O3 and Sb2O3 H2O or CO2 respectively

Q50.The rate of a reaction doubles when its temperature changes from 300K to 310K. Activation energy of such a reaction will be: ​ (R = 8.314 JK−1 mol−1 and log 2= 0.301) JEE Main 2013 (07 Apr) JEE Main Previous Year Paper (1) 58. 5 kJ mol −1 (2) 60. 5 kJ mol −1 (3) 53. 6 kJ mol −1 (4) 48. 6 kJ mol −1

Q51.Trigonal bipyramidal geometry is shown by: (1) XeOF2 (2) XeO3F2 (3) FXeOSO2F (4) [XeF8]2−

Q51.The magnetic moment of the complex anion [Cr(NO) (NH3)(CN)4]2− is : (1) 5.91BM (2) 3.87BM (3) 1.73BM (4) 2.82BM

Q51.In which of the following octahedral complex species the magnitude of Δ0 will be maximum? (1) [Co(H2O)6]2+ (2) [Co(CN)6]3− (3) [Co(C2O4)3]3− (4) [Co(NH3)6]3+

Q51.The coagulating power of electrolytes having ions Na+ , Al3+ and Ba2+ for arsenic sulphide sol increases in the order, (1) Ba2+ < Na+ < Al3+ (2) Al3+ < Na+ < Ba2+ (3) Al3+ < Ba2+ < Na+ (4) Na+ < Ba2+ < Al3+

Q51. XeO4 molecule is tetrahedral having: (1) Two pπ −dπ bonds (2) One pπ −dπ bonds (3) Four pπ −dπ bonds (4) Three pπ −dπ bonds

Q52.Which of the following is diamagnetic ? (1) [Fe(CN)6]3− (2) [Co(ox)3]3− (3) [FeF6]3− (4) [CoF6]3−

Q52.In nucleophilic substitution reaction, order of halogens as incoming (attacking) nucleophile is: I−> Br−> Cl− The order of halogens as departing nucleophile should be : (1) Br−> I−> Cl− (2) I−> Br−> Cl− (3) Cl−> Br−> I− (4) Cl−> I−> Br−

Q52.Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown-red vapours of : (1) CrO3 (2) CrCl3 (3) CrO2Cl2 (4) Cr2O3