Practice Questions

Q26.The number of subshells associated with n = 4 and m = −2 quantum numbers is: (1) 8 (2) 2 (3) 16 (4) 4

Q27.The process that is NOT endothermic in nature is : (1) Ar(g) + e−→Ar−(g) (2) H(g) + e−→H−(g) (3) O− + e−→O2− (g) (g) (4) Na(g) →Na+(g) + e−

Q27.In general, the property (magnitudes only) that shows an opposite trend in comparison to other properties across a period is : (1) lonization enthalpy (2) Electronegativity (3) Electron gain enthalpy (4) Atomic radius

Q27.The correct order of the ionic radii of O2−, N3−, F−, Mg2+, Na+ and Al3+ is : (1) N3−< O2−< F−< Na+ < Mg2* < AI3+ (2) AI3+ < Na+ < Mg2+ < O2−< F−< N3− (3) Al3+ < Mg2+ < Na+ < F−< O2−< N3− (4) N3−< F−< O2−< Mg2+ < Na+ < AI3+

Q27.In the sixth period, the orbitals that are filled are : (1) 6s, 4f, 5d, 6p (2) 6s, 5d, 5f, 6p (3) 6s, 5f, 6d, 6p (4) 6s, 6p, 6d, 6f

Q28.For the reaction Fe2 N(s) + 32 H2(g) ⇌2 Fe(s) + NH3(g) (1) Kc = Kp(RT) (2) Kc = Kp(RT)−1/2 (3) Kc = Kp(RT)1/2 (4) Kc = Kp(RT)3/2

Q28.The value of Kc us 64 at 800 K for the reaction N2(g) + 3H2(g) →2 NH3 (g) The value of Kc for the following reaction is : NH3 (g) →12 N2 (g) + 23 H2 (g) (1) 1/64 (2) 8 (3) 1/4 (4) 1/8

Q28.The ionic radii of O2–, F–, Na+ and Mg2+ are in the order: (1) F– > O2– > Na+ > Mg2+ (2) O2– > F– > Na+ > Mg2+ (3) Mg2+ > Na+ > F– > O2– (4) O2– > F– > Mg2+ > Na+ JEE Main 2020 (04 Sep Shift 1) JEE Main Previous Year Paper

Q28.The acidic, basic and amphoteric oxides, respectively, are (1) Na2O, SO3, Al2O3 (2) Cl2O, CaO, P4O10 (3) N2O3, Li2O, Al2O3 (4) MgO, Cl2O, Al2O3

Q29.The predominant intermolecular forces present in ethyl acetate, a liquid, are: (1) London dispersion and dipole-dipole (2) hydrogen bonding and London dispersion (3) Dipole-dipole and hydrogen bonding (4) London dispersion, dipole-dipole and hydrogen bonding

Q29.In the figure shown below reactant A (represented by square) is in equilibrium with product B (represented by circle). The equilibrium constant is (approx): (1) 4 (2) 8 (3) 1 (4) 2

Q29.Identify the correct labels of A, B and C in the following graph from the options given below: Root mean square speed (Vrms); most proable speed (Vmp); Average speed (Vav) JEE Main 2020 (07 Jan Shift 2) JEE Main Previous Year Paper (1) A −Vmp; B −Vrms; C −Vav (2) A −Vav; B −Vrms; C −Vmp (3) A −Vrms; B −Vmp; C −Vav (4) A −Vmp; B −Vav; C −Vrms

Q30.Match the following compounds (Column-I) with their uses (Column-II) S. No. Column-I S.No. Column-II (I) Ca (OH)2 (A) casts of statues (II) NaCl (B) white wash JEE Main 2020 (06 Sep Shift 2) JEE Main Previous Year Paper (III) CaSO4 ⋅12 H2O (C) antacid (IV) CaCO3 (D) washing soda preparation (1) (I)-(D), (II)-(A), (III)-(C), (IV)-(B) (2) (I)-(B), (II)-(D), (III)-(A), (IV)-(C) (3) (I)-(B), (II)-(C), (III)-(D), (IV)-(A) (4) (I)-(D), (II)-(C), (III)-(B), (IV)-(A)

Q30.The equation that represents the water-gas shift reaction is : (1) CH4(g) + H2O(g) 1270Ni K CO(g) + 3H2(g) (2) 1273K−2C(s) + O2(g) + 4N2(g) → 2 CO(g) + 4N2(g) (3) 1270 K−C(s) + H2O(g) → CO(g) + H2(g) (4) 673K−CO(g) + H2O(g) → CO2(g) + H2(g) catalyst

Q30.The relative strength of the interionic/ intermolecular forces in a decreasing order is: (1) dipole-dipole > ion-dipole > ion-ion (2) ion-dipole > ion-ion > dipole-dipole (3) ion-dipole > dipole-dipole > ion-ion (4) ion-ion > ion-dipole > dipole-dipole

Q30.Among the sulphates of alkaline earth metals, the solubilities of BeSO4 and MgSO4 in water, respectively, are : (1) poor and poor (2) high and poor (3) high and high (4) poor and high

Q30.The redox reaction among the following is (1) formation of ozone from atmospheric oxygen in (2) reaction of [Co(H2O)6]Cl3 with AgNO3 the presence of sunlight (3) reaction of H2SO4 with NaOH (4) combination of dinitrogen with dioxygen at 2000K

Q30.Lattice enthalpy and enthalpy of solution of NaCl are 788 kJmol−1and 4kJmol −1, respectively. The hydration enthalpy of NaCl is: (1) −780 kJmol−1 (2) 780 kJmol−1 (3) −784 kJmol−1 (4) 784 kJmol−1

Q30.If enthalpy of atomization for Br2(l) is x kJ/mol and bond enthalpy for Br2 is y kJ/mol, the relation between them (1) is x = y. (2) does not exist. (3) is x > y. (4) is x < y.

Q31.Oxidation number of potassium in K2O, K2O2 and KO2, respectively, is: (1) +2, + 1 and + 21 (2) +1, + 1 and +1 (3) +1, + 4 and +2 (4) +1, + 2 and +4

Q31.On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are: (1) Li2 O2, Na2 O and K2O2 (2) Li2 O, Na2 O2 and KO2 (3) Li2 O, Na2 O and K2O2 (4) Li2 O, Na2 O2 and K2O

Q31.If the equilibrium constant for A ⇌B + C is K(1)eq and that of B + C ⇌P is K(2)eq , the equilibrium constant for A ⇌P is : (1) K(1)eq /K(2)eq (2) K(2)eq −K(1)eq (3) K(1)eq + K(2)eq (4) K(1)eq K(2)eq

Q31.Hydrogen peroxide, in the pure state, is : (1) non–planar and almost colorless (2) Linear and blue in color (3) Linear and almost colorless (4) planar and blue in color

Q32.The compound that cannot act both as oxidizing and reducing agent is (1) H3PO4 (2) H NO2 (3) H2SO3 (4) H2O2 Q33.‘ X ’ melts at low temperature and is a bad conductor of electricity in both liquid and solid state. X is: (1) zinc sulphide (2) Mercury (3) Silicon carbide (4) Carbon tetrachloride

Q32.The radius of the second Bohr orbit, in terms of the Bohr radius, a0, in Li2+ is: (1) 2a0 (2) 4a0 3 9 (3) 4a0 (4) 2a0 3 9