Practice Questions

Q79.Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture? (1) 1.20 M (2) 1.50 M (3) 1.344 M (4) 2.70 M

Q84.Which of the following statements in relation to the hydrogen atom is correct? (1) 3s orbital is lower in energy than 3p orbital (2) 3p orbital is lower in energy than 3d orbital (3) 3s and 3p orbitals are of lower energy than 3d (4) 3s, 3p and 3d orbitals all have the same energy orbital

Q87.Which of the following oxides is amphoteric in character? (1) CaO (2) CO2 (3) SiO2 (4) SnO2

Q89.Lattice energy of an ionic compounds depends upon (1) Charge on the ion only (2) Size of the ion only (3) Packing of ions only (4) Charge on the ion and size of the ion

Q92.Benzene and toluene form nearly ideal solutions. At 20∘C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20∘C for a solution containing 78 g of benzene and 46 g of toluene in torr is (1) 50 (2) 25 (3) 37.5 (4) 53.5

Q93.Consider an endothermic reaction, X ⟶Y with the activation energies Eb and Ef for the backward and forward reactions, respectively. In general (1) Eb < Ef (2) Eb > Ef (3) Eb = Ef (4) There is no definite relation between Eb and Ef

Q94.Consider the reaction: N2 + 3H2 ⟶2NH3 carried out at constant temperature and pressure. If ΔH and ΔU are the enthalpy and internal energy changes for the reaction, which of the following expressions is true? (1) ΔH = 0 (2) ΔH = ΔU (3) ΔH < ΔU (4) ΔH > ΔU

Q97.For the reaction 2NO2( g) ⇌2NO(g) + O2( g), (Kc = 1.8 × 10−6at 184C) (R = 0.0831 kJ/(mol. K) When Kp and Kc are compared at 184∘C, it is found that (1) Kp is greater than Kc (2) Kp is less than Kc (3) Kp = Kc (4) Whether Kp is greater than, less than or equal to Kc depends upon the total gas pressure JEE Main 2005 JEE Main Previous Year Paper

Q49.The electrochemical equivalent of a metal is 3.3 × 10−7 kg per coulomb. The mass of the metal liberated at the cathode when a 3 A current is passed for 2 seconds will be (1) 19.8 × 10−7 kg (2) 9.9 × 10−7 kg (3) 6.6 × 10−7 kg (4) 1.1 × 10−7 kg

Q79.Which of the following sets of quantum numbers is correct for an electron in 4f orbital? (1) n = 4, l = 3, m = +4, s = + 12 (2) n = 3, I = 2, m = −2, S = + 12 (3) n = 4, I = 3, m = +1, s = + 12 (4) n = 4, I = 4, m −4, s = −12

Q82.Which one the following sets of ions represents the collection of isoelectronic species? (1) K+, Ca2+, Sc3+, Cl− (2) Na+, Mg2+, Al3+, Cl− (3) K+, Cl−, Mg2+, Sc3+ (4) Na+, Ca2+, Sc3+, F−

Q86.The bond order in NO is 2.5 while that in NO+ is 3 . Which of the following statements is true for these two species? (1) Bond length in NO+ is greater than in NO (2) Bond length is unpredictable (3) Bond length in NO+ in equal to that in NO (4) Bond length in NO is greater than in NO+

Q91.Which one the following does not have sp2 hybridized carbon? (1) Acetone (2) Acetamide (3) Acetonitrile (4) Acetic acid

Q92.As the temperature is raised from 20∘C to 40∘C, the average kinetic energy of neon atoms changes by a factor of which of the following? (1) 1/2 (2) 2 (3) 293313 (4) √313293

Q93.In Vander Waals equation of state of the gas law, the constant ' b ' is a measure of (1) intermolecular repulsions (2) intermolecular collisions per unit volume (3) Volume occupied by the molecules (4) intermolecular attraction

Q95.An ideal gas expands in volume from 1 × 10−3 m3 to 1 × 10−2 m3 at 300 K against a constant pressure of 1 × 105Nm−2 . The work done is (1) −900 J (2) 900 kJ (3) 2780 kJ (4) −900 kJ

Q97.What is the equilibrium expression for the reaction P4( s) + 5O2( g) ⇌P4O10( s ? (1) Kc = [P4O10]/P4][O2]5 (2) Kc = 1/[O2]5 (3) Kc = [O2]5 (4) Kc = [P4O10]/5 [P4] [O2]

Q98.For the reaction, CO(g) + Cl2( g) ⇌COCl2( g) the KpKc is equal to JEE Main 2004 JEE Main Previous Year Paper (1) 1 (2) 1.0 RT (3) √RT (4) RT

Q68.Which of the following atoms has the lowest ionization potential? (1) 147 N (2) 13355 Cs (3) 4018Ar (4) 168 O

Q82.Which one of the following groupings represents a collection of isoelectronic species? (At. nos,: 55, Br:35) (1) N3−, F−, Na+ (2) Be, Al3+, Cl− (3) Ca2+, Cs+, Br (4) Na+, Ca2+, Mg2+

Q83.In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen (1) 5 →2 (2) 4 →1 (3) 2 →5 (4) 3 →2

Q87.Which one of the following substances has the highest proton affinity? (1) H2 S (2) NH3 (3) PH3 (4) H2O

Q95.The correct relationship between free energy change in a reaction and the corresponding equilibrium constant Kc is (1) −ΔG = RT ln Kc (2) ΔG0 = RT ln Kc (3) −ΔG0 = RT In Kc (4) ΔG = RT ln Kc

Q97.For the reaction equilibrium N2O4( g) ⇌2NO2( g) the concentrations of N2O4 and NO2 at equilibrium are 4.8 × 10−2 and 1.2 × 10−2 mol L−1 respectively. The value of Kc for the reaction is (1) 3 × 10−1 mol L−1 (2) 3 × 10−3 mol L−1 (3) 3 × 103 mol L−1 (4) 3.3 × 102 mol L−1

Q58.The mass of product liberated on anode in an electrochemical cell depends on (where t is the time period, for which the current is passed) (1) (It)1/2 (2) IT (3) I/t (4) I2t