Practice Questions

Q33.The correct order of the first ionization enthalpies is: (1) Ti < Mn < Zn < Ni (2) Ti < Mn < Ni < Zn (3) Mn < Ti < Zn < Ni (4) Zn < Ni < Mn < Ti JEE Main 2019 (10 Apr Shift 2) JEE Main Previous Year Paper

Q33.The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are: (1) 15,6 and 2 (2) 16,6 and 3 (3) 16,5 and 2 (4) 15,5 and 3

Q33.The process with negative entropy change is: (1) Synthesis of ammonia from N2 and H2 . (2) Dissolution of iodine in water. (3) Dissociation of CaSO4 (s) to CaO (s) and (4) Sublimation of dry ice. SO3 (g).

Q33.The correct option with respect to the Pauling electronegativity values of the elements is: (1) Te > Se (2) Ga < Ge (3) Si < Al (4) P > S

Q33.If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength λ, then for 1.5 p momentum of the photoelectron, the wavelength of the light should be: (Assume kinetic energy of ejected photoelectron to be very high in comparison to work function) 4 3 (1) 9λ (2) 4λ (3) 2 (4) 1 3λ 2λ JEE Main 2019 (08 Apr Shift 2) JEE Main Previous Year Paper

Q33.In comparison to boron, berylium has: (1) greater nuclear charge and lesser first ionisation enthalpy (2) lesser nuclear charge and greater first ionisation enthalpy (3) lesser nuclear charge and lesser first ionisation enthalpy. (4) greater nuclear charge and greater first ionisation enthalpy.

Q33.Two pi and half sigma bonds are present in: (1) O−2 (2) N 2+ (3) N2 (4) O2

Q33.The element having the greatest difference between its first and second ionization energies, is (1) Ba (2) K (3) Ca (4) Sc

Q33.The isoelectronic set of ions is: (1) F−, Li+, Na+ and Mg2+ (2) N3−, Li+, Mg2+ and O2− (3) N3−, O2−, F− and Na+ (4) Li+, Na+, O2− and F−

Q33.Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in +1 and +3 oxidation states. This is due to: (1) Diagonal relationship (2) Lattice effect (3) Lanthanoid contraction (4) Inert pair effect

Q33.Which one of the following equations does not correctly represent the first law of thermodynamics for the given processes involving an ideal gas? (Assume non- expansion work is zero) (1) Isochoric process : (2) Isochoric process : (3) Cyclic process : (4) Adiabatic process : ΔU = q q = – w q = – w ΔU = - w

Q33.The correct order of the atomic radii of C, Cs, Al, and S is: (1) C < S < A1 < Cs (2) S < C < Cs < Al (3) S < C < Al < Cs (4) C < S < Cs < Al

Q33.The element that does not show catenation is (1) Sn (2) Si (3) Ge (4) Pb

Q33.Given: On the basis of data given above, predict which of the following gases shows the least adsorption on a definite amount of charcoal? (1) CH4 (2) CO2 (3) SO2 (4) H2

Q33.When the first electron gain enthalpy (ΔHeg) of oxygen is −141 kJ/mol , its second electron gain enthalpy is: (1) A positive value (2) Almost the same as that of the first (3) Negative, but less negative than the first (4) A more negative value than the first

Q33.Among the following species, the diamagnetic molecule is: (1) CO (2) B2 (3) O2 (4) NO

Q34.The correct statement among the following is: JEE Main 2019 (12 Apr Shift 1) JEE Main Previous Year Paper (1) SiH33N is planar and less basic than CH33N (2) SiH33N is pyramidal and more basic than CH33N (3) SiH33N is pyramidal and less basic than CH33N (4) SiH33N is planar and more basic than CH33N

Q34.Points I, II and III in the following plot respectively correspond to (Vmp: most probable velocity) (1) Vmp of N2300 K; Vmp of H2300 K; Vmp of (2) Vmp of H2300 K; Vmp of N2300 K; Vmp of O2400 K; O2400 K; (3) Vmp of N2300 K; Vmp of O2400 K; Vmp of (4) Vmp of O2400 K; Vmp of N2300 K; Vmp of H2300 K; H2300 K;

Q34.The IUPAC symbol for the element with atomic number 119 would be: (1) Unh (2) Uun (3) Une (4) Uue

Q34.At a given temperature T, gases Ne, Ar, Xe and Kr are found to deviate from ideal gas behaviour. Their equation of state is given as p = V−bRT at T. Here, b is the van der Waals constant. Which gas will exhibit steepest increase in the plot of Z (compression factor) vs p? (1) Ne (2) Kr (3) Ar (4) Xe

Q34.An ideal gas undergoes isothermal compression from 5 m3 to 1 m3 against a constant external pressure of 4 N m−2 . The heat released in this process is 24 J mol−1 K−1 and is used to increase the pressure of 1 mole of Al. The temperature of Al increases by: (1) 2 K (2) 1 K 3 (3) 3 2 K (4) 2 K Q35. 5 .1 g NH4 SH is introduced in 3 .0 L evacuated flask at 327oC . 30% of the solid NH4 SH is decomposed to NH3 and H2S as gases. The KP of the reaction at 327oC is (R = 0 .082 L atm mol−1 K−1, Molar mass of S = 32 g mol−1, Molar mass of N = 14 g mol−1) (1) 0 .242 atm2 (2) 0 .242 ×10−4 atm2 (3) 1 × 10−4 atm2 (4) 4 .9 ×10−3 atm2

Q34.The reaction MgO(s) + C(s) →Mg(s) + CO(g), for which ΔH∘= +491.1 kJ mol−1 and ΔS∘= 198.0JK−1 mol−1 is not feasible at 298 K. Temperature above which reaction will be feasible is (1) 2040.5 K (2) 1890.0 K (3) 2480.3 K (4) 2380.5 K

Q34.The incorrect match in the following is: (1) ΔG0 < 0, K > 1 (2) ΔG0 > 0, K < 1 (3) ΔG0 = 0, K = 1 (4) ΔG0 < 0, K < 1

Q34.For silver, Cp (JK-1mol-1 ) = 23 + 0.01T . If the temperature T of 3 moles of silver is raised from 300 K to 1000 K at 1 atm pressure, the value of ΔH will be close to: JEE Main 2019 (08 Apr Shift 1) JEE Main Previous Year Paper (1) 16 kJ (2) 62 kJ (3) 13 kJ (4) 21 kJ

Q34.A process has ΔH = 200 J mol−1 and ΔS = 40 JK −1mol−1. Out of the values given below choose the minimum temperature above which the process will be spontaneous: (1) 20 K (2) 5K (3) 12K (4) 4K