Order intermolecular forces of attraction are negligible 82. The figure shows a narrow tube kept horizontally with air column of 10 cm in length trapped by 8 cm of mercury column. The pressure of air outside is 0.96 atm. [1 atm = 76 cm of Hg]. If the tube is kept in a slanting position at 45q to the vertical with the open end up, […]

Order Atomic Structure Assignment 31. Of the following Statements, the one, not proposed by Sir John Dalton in the atomic theory is (a) Atoms are indivisible (b) Atoms of same element are identical in all respects (c) The mass of an atom can be changed into energy (d) Atoms are smallest particle that take part in a chemical reaction 32. Consider an atom of atomic […]

Order Magnetic Quantum Number Assignment 54. The number of revolutions made by an electron per second in the third orbit of hydrogen atom is (In the first orbit of hydrogen atom, velocity = 2.18 u 106 m/s and radius = 0.53 Å) (a) 2.42 u 1014 (b) 2.42 u 106 (c) 2.42 u 1010 (d) 2.42 u 104 55. The velocity of an electron in […]

Order Chemical Bonding Assignment 1. PCl5 has trigonal bipyramidal shape, but ,F5 has square pyramidal shape. Explain. 2. A compound AB3 is triangular planar. When B is added it becomes AB4 . When B is removed from AB3 , it becomes AB2 . What are the geometries of AB4 and AB2 ? 3. Hydrogen is diatomic but He is monatomic. Explain using M.O. theory. 4. […]

Types of covalent bond assignment 54. The repulsion between two lone pairs is greater than that between two bond pairs because (a) shape of molecule determines the repulsion (b) lone pair is attracted to only one nucleus (c) lone pair causes distortion of bond angles (d) lone pairs are formed by hybridized orbitals 55. The magnitude of repulsions between bond pairs depends on (a) number […]

Order Chemical Energetics and Thermodynamics Assignment 1. Calculate the work done in calories in the isothermal expansion of a system by one litre at the constant pressure of 740 mm T = 298 K. 2. ‘Hf values for C2 H2(g) and C2 H6(g) are 47.0 k cal mol1 and 29.3 k cal mol1 respectively. Calculate for the reaction C2 H2(g) 2H2(g)oC2 H6(g) both ‘H and […]

Order Homogeneous and heterogeneous systems 66. In a reversible Carnot cycle, W = 150 kJ; Q(supplied) at T1 = 225 kJ . Calculate (i) efficiency and (ii) the lower temperature, T2 K . (T1 = 227qC) (a) 0.5; 150 (b) 0.75; 170 (c) 0.75 ; 180 (d) 0.67 ; 299 67. An ideal gas at 3 atm pressure and 300K is expanded isothermally and reversibly […]

Order Chemical and Ionic Equilibria Discussion 1. The forward reaction in the system 2NH3(g) N2(g) 3H2(g) has proceeded to 98% under equilibrium. The equilibrium pressure = 10 atm. Temperature = 400qC. Calculate KP and KC. 2. 3 moles of Iodine and 8 moles of hydrogen are kept at 444qC and at constant volume till equilibrium is established at which 5.65 moles of H, (g) are […]

Order Hydrolysis of salts of weak acid 33. At 40qC and a total equilibrium pressure of 1 atm, N2 O4(g) is dissociated to the extent of 60%: N2 O4(g) 2NO2(g). Calculate the % dissociation at an equilibrium pressure of 5 atm (a) ~42% (b) ~32% (c) ~48% (d) ~21% 34. For a certain gaseous equilibrium, n1 A(g) n2 B(g) n3 C(g) considering pressure in atmosphere […]

Order Dilute Solutions and Electrochemistry 1. Dry air was bubbled successively through a solution containing 0.018 kg of an ideal nonvolatile solute in 0.1 kg water and pure water for sometime. The loss of mass of solution was 2.94 g and that of the pure solvent 60 mg. What is the ratio of the molar mass of solute to that of the solvent? (Assume the […]