Practice Questions

Q35.For the decomposition of the compound, represented as NH2COONH4(s) ⇌2NH3(g) + CO2(g) the Kp = 2 .9 ×10−5 atm3 . If the reaction is started with 1 mole of the compound, the total pressure at equilibrium would be : (1) 7 .66 ×10−2 atm (2) 38 .8 ×10−2 atm (3) 5 .82 ×10−2 atm (4) 1 .94 ×10−2 atm

Q35.Similarity in chemical properties of the atoms of elements in a group of the Periodic table is most closely related to: (1) atomic numbers (2) atomic masses (3) number of principal energy levels (4) number of valence electrons

Q35.The correct order of bond dissociation energy among N2, O2, O−2 is shown in which of the following arrangements? (1) N2 > O−2 > O2 (2) O−2 > O2 > N2 (3) N2 > O2 > O−2 (4) O2 > O−2 > N2

Q36.Which of the following has unpaired electron(s)? (1) O−2 (2) N2+2 (3) O2−2 (4) N2

Q36.Which one of the following does not have a pyramidal shape? (1) (CH3)3 N (2) (SiH3)3 N (3) P(CH3)3 (4) P(SiH3)3

Q36.For complete combustion of ethanol, C2H5OH(l) + 3O2(g) →2CO2(g) + 3H2O(l), the amount of heat produced as measured in bomb calorimeter, is 1364.47 kJ mol−1 at 25℃ . Assuming ideality the Enthalpy of combustion, ΔcH , for the reaction will be: (R = 8.314 kJ mol−1) (1) −1366.95 kJ mol−1 (2) −1361.95 kJ mol−1 (3) −1460.50 kJ mol−1 (4) −1350.50 kJ mol−1

Q36.Zirconium phosphate [Zr3 (PO4)4] dissociates into three zirconium cations of charge​ +4 and four phosphate anions of charge −3. If molar solubility of zirconium phosphate is denoted by s and its solubility product by Ksp then which of the following relationship between s and Ksp is correct ​? (1) S = {Ksp/6912}7 (2) S = {Ksp/144}1/7 (3) S = {Ksp/(6912)1/7} (4) S = (Ksp/6912)1/7

Q36.Which of the following arrangements represents the increasing order (smallest to largest) of ionic radii of the given species O2−, S2−, N3−, P3− ? JEE Main 2014 (12 Apr Online) JEE Main Previous Year Paper (1) O2−< N3−< S2−< P3− (2) O2−< P3−< N3−< S2− (3) N3 < O2−< P3−< S2− (4) N3−< S2−< O2−< P3−

Q37.The temperature at which oxygen molecules have the same root mean square speed as helium atoms have at 300 K is : (Atomic masses : He = 4 u, O = 16 u) (1) 600 K (2) 2400 K (3) 1200 K (4) 300 K

Q37.How many electrons are involved in the following redox reaction ? Cr2O2−7 + Fe2+ + C2O2−4 →Cr3 + + Fe3+ + CO2 (Unbalanced) (1) 6 (2) 5 (3) 3 (4) 4

Q37.Which of the following molecules has two sigma (σ) and two pi (π) bonds? (1) C2H4 (2) N2 F2 (3) C2H2Cl2 (4) HCN

Q37.For the reaction SO2(g) + 12 O2(g) ⇌SO3(g) , if KP = KC(RT)x where the symbols have usual meaning then the value of x is: (assuming ideality) (1) −1 (2) −12 (3) 1 (4) 1 2

Q37.In allene (C3H4), the type(s) of hybridization of the carbon atoms is (are) : (1) sp and sp3 (2) sp2 and sp (3) only sp2 (4) sp2 and sp3

Q38.In which of the following reactions H2O2 acts as a reducing agent ? (a) H2O2 + 2H+ + 2e−→2H2O (b) H2O2 −2e−→O2 + 2H+ (c) H2O2 + 2e−→2OH− (d) H2O2 + 2OH−−2e−→O2 + 2H2O (1) (a) , (b) (2) (c) , (d) (3) (a) , (c) (4) (b) , (d)

Q38.Van der Waal's equation for a gas is stated as, nRT n 2 P = V−nb −a( V ) . JEE Main 2014 (09 Apr Online) JEE Main Previous Year Paper This equation reduces to the perfect gas equation, P = nRTV When, (1) temperature is sufficiently high and pressure is (2) both temperature and pressure are very low. low. (3) both temperature and pressure are very high. (4) temperature is sufficiently low and pressure is high.

Q38.Consider the reaction : H2SO3(aq) + Sn4+(aq) + H2O(l) →Sn2+(aq) + HSO−4(aq) + 3H+(aq) Which of the following statements is correct ? (1) Sn4+ is the oxidizing agent because it undergoes (2) Sn4+ is the reducing agent because it undergoes oxidation oxidation (3) H2SO3 is the reducing agent because it (4) H2SO3 is the reducing agent because it undergoes reduction undergoes oxidation

Q38.The (S∘) of the following substances are: CH4 g)186.2JK−1 mol−1 O2 (g) 205.2JK−1 mol−1 CO2( g)213.6JK−1 mol−1 H2O(g) 69.9.JK −1 mol−1 The entropy change (ΔS∘) for the reaction CH4( g) + 2O2( g) →CO2( g) + 2H2O (l) is: (1) −312.5 J K−1 mol−1 (2) −242.8JK−1 mol−1 (3) −108.1JK−1 mol−1 (4) −37.6 J K−1 mol−1

Q38.The initial volume of a gas cylinder is 750.0 mL. If the pressure of gas inside the cylinder changes from 840.0 mmHg to 360.0 mmHg, the final volume the gas will be: (1) 1.750 L (2) 3.60 L (3) 4.032 L (4) 7.50 L

Q39.The standard enthalpy of formation of NH3 is − 46. 0 kJ / mol. If bond enthalpy of H2 is −436 kJ / mol and that of N2 is −712 kJ / mol , the average bond enthalpy of N −H bond in NH3 is : (1) − 964 kJ / mol (2) − 1102 kJ / mol (3) + 1056 kJ / mol (4) + 352 kJ / mol

Q39.For the estimation of nitrogen, 1. 4 g of an organic compound was digested by the Kjeldahl method and the evolved ammonia was absorbed in 60 ml of 10M sulphuric acid. The unreacted acid required 20 ml of 10M sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is (1) 6% (2) 10% (3) 3% (4) 5%

Q39.Amongst LiCl, RbCl, BeCl2 and MgCl2 the compounds with the greatest and the least ionic character, respectively are : (1) MgCl2 and BeCl2 (2) RbCl and MgCl2 (3) LiCl and RbCl (4) RbCl and BeCl2

Q39.The standard enthalpy of formation (ΔfH∘298) for methane, CH4 is −74.9 kJ mol−1 . In order to calculate the average energy given out in the formation of a C −H bond from this it is necessary to know which one of the following? (1) The dissociation energy of the hydrogen (2) The first four ionisation energies of carbon. molecule, H2 . (3) The dissociation energy of H2 and enthalpy and (4) The first four ionisation energies of carbon and sublimation of carbon (graphite). electron affinity of hydrogen.

Q39.The molar heat capacity (Cp) of CD2O is 10 cals at 1000 K. The change in entropy associated with cooling of 32 g of CD2O vapour from 1000 K to 100 K at constant pressure will be: (D = deuterium, atomic mass = 2u) (1) 23.03caldeg−1 (2) −23.03caldeg−1 (3) 2.303caldeg−1 (4) −2.303caldeg−1

Q40.At a certain temperature, only 50% HI is dissociated into H2 and I2 at equilibrium. The equilibrium constant is : (1) 0.5 (2) 4.0 (3) 1.0 (4) 0.25

Q40.What happens when an inert gas is added to an equilibrium keeping volume unchanged? (1) More product will form (2) Less product will form (3) More reactant will form (4) Equilibrium will remain unchanged