Practice Questions

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

Q28.The true statement amongst the following is: (1) Both ΔS and S are functions of temperature. (2) Both S and ΔS are not functions of temperature (3) S is not a function of temperature but ΔS is a function of temperature (4) S is a function of temperature but ΔS is not a function of temperature

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

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

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.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.

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 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.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.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.Five moles of an ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is : (1) Cv(T2 −T1) (2) −RT(V2 −V1) (3) −RT ln V2/V1 (4) Zero

Q30.A mixture of one mole each of H2 , He and O2 each are enclosed in a cylinder of volume V at temperature T. If the partial pressure of H2 is 2 atm, the total pressure of the gases in the cylinder is: (1) 6 atm (2) 38 atm (3) 14 atm (4) 22 atm Q31. 100 mL of 0. 1 M HCl is taken in a beaker and to it 100 mL 0. 1 M NaOH of is added in steps of 2 mL and the pH is continuously measured. Which of the following graphs correctly depicts the change in pH ? (1) (2) (3) (4)

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

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

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.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

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.While titration dilute HCI solution with aqueous NaOH, which of the following will not be required ? (1) Burette and porcelain tile (2) Pipette and distilled water (3) Clamp and phenolphthalein (4) Bunsen burner and measuring cyclinder

Q32.The one that is NOT suitable for the removal of permanent hardness of water is : (1) Clark's method (2) Ion–exchange method (3) Calgon's method (4) Treatment with sodium carbonate