Practice Questions

Q32.Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying 0. 5 V , when the radiation of 250 nm is used. The work function of the metal is (1) 4 eV (2) 5. 5 eV (3) 4. 5 eV (4) 5 eV

Q33.Which of the following conversions involves change in both shape and hybridisation? (1) H2O → H3O+ (2) BF3 →BF 4− (3) CH4 → C2H6 (4) NH3 → NH+4

Q33.The correct order of electron affinity is: (1) O > F > Cl (2) F > O > Cl (3) F > Cl > O (4) Cl > F > O JEE Main 2018 (15 Apr Shift 2 Online) JEE Main Previous Year Paper

Q34.The most polar compound among the following is: JEE Main 2018 (16 Apr Online) JEE Main Previous Year Paper (1) (2) (3) (4)

Q34.Total number of lone pair of electrons in I3− ion is: (1) 12 (2) 3 (3) 6 (4) 9

Q34.In the molecular orbital diagram for the molecular ion N+2 , the number of electrons in the σ2p molecular orbital is JEE Main 2018 (15 Apr) JEE Main Previous Year Paper (1) 0 (2) 2 (3) 3 (4) 1

Q34.In the molecular orbital diagram for the molecular ion, N+2 , the number of electrons in the σ2p molecular orbital is : (1) 0 (2) 2 (3) 3 (4) 1

Q34. Which of the following best describes the diagram of molecular orbital? (1) A bonding π orbital (2) A non-bonding orbital (3) An antibonding σ orbital (4) An antibonding π orbital Q35. ΔfG∘ at 500 K for substance ' S ' in liquid state and gaseous state are +100.7kcalmol−1 and +103 kcalmol−1 , respectively. Vapour pressure of liquid ' S ' at 500 K is approximately equal to: (R = 2calK−1 mol−1). (1) 100 atm (2) 1 atm (3) 10 atm (4) 0.1 atm

Q35.Identify the pair in which the geometry of the species is T-shape and square pyramidal, respectively JEE Main 2018 (15 Apr Shift 1 Online) JEE Main Previous Year Paper (1) ICl−2 and ICl5 (2) IO−3 and IO2F−2 (3) ClF3 and IO−4 (4) XeOF2 and XeOF4

Q35.The combustion of benzene (l) gives CO2(g) and H2O(l). Given that heat of combustion of benzene at constant volume is −3263 .9 kJ mol−1 at 25°C; the heat of combustion (in kJ mol−1) of benzene at constant pressure will be (R = 8 .314 JK−1 mol−1) (1) −3267.6 (2) 4152.6 (3) −452.46 (4) 3260

Q35.Identify the pair in which the geometry of the species is T-shaped and square-pyramidal, respectively, (1) ICl−2 and ICl5. (2) IO−3 and IO2 F−2 . (3) ClF3 and IO−4 . (4) XeOF2 and XeOF4.

Q36. In the above compound, the bond orders of bonds (I) and (II) are: (1) (I) < 2, (II) > 2 (2) (I) > 2, (II) > 2 (3) (I) > 2, (II) < 2 (4) (I) < 2, (II) < 2

Q36.Given (i) 2Fe2O3( s) →4Fe(s) + 3O2( g); ΔrG∘= +1487.0 kJ mol−1 (ii) 2CO(g) + O2( g) →2CO2( g); ΔrG∘= −514.4 kJ mol−1 Free energy change, ΔrG∘ for the reaction 2Fe2O3( s) + 6CO(g) →4Fe(s) + 6CO2( g) will be: (1) −112.4 kJ mol−1 (2) −56.2 kJ mol−1 (3) −208.0 kJ mol−1 (4) −168.2 kJ mol−1

Q36. In hydrogen azide, the bond orders of bonds (I) and (II) are ______. (1) I < 2, II > 2 (2) I > 2, II > 2 (3) I > 2, II < 2 (4) I < 2, II < 2

Q36.Which of the following lines correctly show the temperature dependence of equilibrium constant K, for an exothermic reaction? (1) A & D (2) A & B (3) B & C (4) C & D

Q37.An aqueous solution contains 0. 10 M H2S and 0. 20 M HCl. If the equilibrium constant for the formation of HS− from H2S is 1.0 × 10−7 and that of S2− from HS− ions is 1.2 × 10−13 , then, the concentration of S2− ions in the aqueous solution is: (1) 5 × 10−19 (2) 5 × 10−8 (3) 3 × 10−20 (4) 6 × 10−21

Q38.For which of the following processes, ΔS is negative? (1) C (diamond) →C (graphite) (2) N2(g, 1 atm) →N2(g, 5 atm) (3) N2(g, 273K) →N2(g, 300K) (4) H2(g) →2H(g)

Q38.Following four solutions are prepared by mixing different volumes of NaOH and HCl of different concentrations, pH of which one of them will be equal to 1 ? (1) 55 mL 10M HCl + 45 mL 10M NaOH (2) 75 mL M5 HCl + 25 mL M5 NaOH (3) 100 mL 10M HCl + 100 mL 10M NaOH (4) 60 mL 10M HCl + 40 mL 10M NaOH

Q38.The decreasing order of bond angles in BF3, NH3, PF3 and I−3 is: (1) I−3 > BF3 > NH3 > PF3 (2) BF3 > I−3 > PF3 > NH3 (3) BF3 > NH3 > PF3 > I−3 (4) I−3 > NH3 > PF3 > BF3

Q38.An aqueous solution contains an unknown concentration of Ba2+ . When 50 mL of a 1 M solution of Na2 SO4 is added, BaSO4 just begins to precipitate. The final volume is 500 mL. The solubility product of BaSO4 is 1 × 10−10 . What is the original concentration of Ba2+ ? (1) 1 .0 ×10−10M (2) 5 × 10−9M (3) 2 × 10−9M (4) 1 .1 ×10−9M

Q38.The decreasing order of bond angles in BF3, NH3, PF3 and I−3 is : (1) I−3 > BF3 > NH3 > PF3 (2) BF3 > I−3 > PF3 > NH3 (3) BF3 > NH3 > PF3 > I−3 (4) I−3 > NH3 > PF3 > BF3

Q40.The gas phase reaction 2 NO2(g) → N2O4 (g) is an exothermic reaction. The decomposition of N2O4 , in equilibrium mixture of NO2 (g) and N2O4 (g) can be increased by: (1) Addition of an inert gas at constant pressure (2) Lowering the temperature (3) Increasing the pressure (4) Addition of an inert gas at constant volume

Q40.Which of the following salts is the most basic in aqueous solution? JEE Main 2018 (08 Apr) JEE Main Previous Year Paper (1) Pb (CH3 COO)2 (2) Al (CN)3 (3) CH3 COOK (4) FeCl3

Q40.Lithium aluminium hydride reacts with silicon tetrachloride to form: (1) LiCl, AlH3 and SiH4 (2) LiCl, AlCl3 and SiH4 (3) LiH, AlCl3 and SiCl2 (4) LiH, AlH3 and SiH4 JEE Main 2018 (15 Apr Shift 2 Online) JEE Main Previous Year Paper

Q40.An ideal gas undergoes a cyclic process as shown in the figure ΔUBC = −5 KJmol−1, qAB = 2 KJmol−1 WAB = −5 KJmol−1, WCA = 3 KJmol−1 Heat absorbed by the system during process CA is (1) −5 KJmol−1 (2) +5 KJmol−1 (3) −18 KJmol−1 (4) 18 KJmol−1